Of course, I have a feeling you aren't considering using a Bishop as a front line melee fighter; I am. This would be along with a more standard elven Bishop who focuses on INT/SPD and mainly uses magic.

Some thoughts:
* The battle bishop would end up focusing on Mage and Priest spells early on, as that's where the bulk of the good non-combat spells lie.
* This, then, would push the other Bishop into being Alchemy/Psionics early on, which tends to be a bit more unorthodox. No reason it wouldn't work, and that set-up would cover every realm except Divine Magic reasonably well. (Or should I get some Mage early for Freeze Flesh and Fireball, not to mention Noxious Fumes?)
* Roles and specializations might shift a bit. Later on, there's more practice per level available; the pure caster can branch out into other spell types (Mage is great around level 10 with Fireball being good at that point (Fire Bomb not yet that good), while Priest becomes really good starting at 11, though Superman could be worth learning before then), while the battle one starts using more damage spells, particularly since there's a gap between the maces available in Arnika and the likes of Diamond Eyes and The Mauler.
* Bishops are frail; they have the lowest HP of any class that could realistically go in the front ranks. For this reason, I would definitely give the character a shield and some shield skill. (Apparently there's no benefit past 50 with the shields a Bishop can equip, unless you get the *Light* *Shield*.)
* The whole reason the Bishop in the front line setup makes any sense at all is that Bishops actually have decent (by mage standards) equipment; they can use some shields, there's AC 9 body armor available (later replaced with AC 6 Robes of Rejuvenation, but by then accessories can fill that gap, and HP isn't as much of an issue), and weapon selection includes maces, including The Mauler, which is the strongest buyable weapon (and I believe the strongest reliably available weapon (that is, not counting those only available via random drops or random treasures)).

I plan on going with my old party setup, maybe with some better foresight this time around. Such as, like you said, not giving the Rogue the Bloodlust, and instead allowing him to use weapons from range. Also, not having the Rogue focus on Locks and Traps, despite his bonus: He has a lot of skills to work on. Perhaps the Gadgeteer would be better for that, as she has less skills to develop.
I agree with your Bishop setup. I tend to do what you said, max out Intelligence for Powercast, and Speed for Snakespeed first. Then Piety for more SPs, Stamina, and Iron Will, and Senses for Initiative, chance to hit, and Eagle Eye. Lastly, by level 30 or so, I can put 2 points per level into the last 3: Vitality, Dexterity, and Strength, because that's all that remains.
Doing 2 Bishops is a good idea, as you have 2 casters. However, with their extreme experience penalty, I would suggest eventually branching out into all 4 spellbooks with both to take full advantage of their profession.
I wonder if I should go with Staff and Wand, in preparation for the Staff of Doom(using the extended range Quarterstaff is a good way to train this), or go with Mace and Flail. The problem with the second option is that you actually have to go into melee range to use it, and as you said, Bishops are probably the most frail class to melee with(you would never melee with a Mage, Psionic, or Alchemist, unless they get the Staff of Doom, as they have terrible weapon choices). Perhaps you can get lucky and get a Bullwhip, and attack from extended range to train Mace and Flail.
If I do go Mace and Flail, and get lucky with the Bullwhip, I can equip a Round Shield, the best shield for a while. I will probably grind Jan-Ette for the *Light* *Shield* in that case. For armor, I will try to give the Bishop the best armor available. They can wear decent armor, for caster standards. They can actually wear gloves and shields, unlike the Mage and Psionic. They can wear the Leather Helm, Studded Hauberk, Stud Chausses, and Leather Boots, all available early from Antone, the best you can get for a while.

I do tend to eventually branch off into all 4 spellbooks, but early on it helps to have some focus.

Of course, I've been toying with the idea of replacing the Valkyrie or Ranger with yet another Bishop, albeit the Fairy Mage->Bishop (at level 2) setup for early Power Cast. That would be 3 Bishops, albeit one that's a level behind on non-Mage spells. That change would put the party into a more magic damage focus at that point, I'd think.

(Maybe bring back the idea of Fighter replaced with Gadgeteer? Problem is that I can't put the Bard, Fighter, Ranger/Valkyrie, *and* one of the Bishops in the front at the same time. (Yes, I still want to try using a Bishop in the front, as a melee attacker.))

Worth noting that Alchemist does get more HP than Bishop.

Also, Staff of Doom wielding Alchemists do have one advantage; there is a Medicine Bag, which grants HP regen, and is conveniently located at the same place as the Staff of Doom. Only Alchemists can use that Medicine Bag, but for them it's quite convenient. (The Amulet of Healing is still better, however.)

I don't bother with Piety. The effect of Piety on SP is relatively minor at higher levels, and a Bishop, in particular, does not need any more SP. (Every spell learned grants SP, and Bishops also have all of their spellbook skills contributing toward SP rather than just one.) I consider Senses (for more initiative) to be more important than Piety here.

I was thinking of doing a fun setup that I used to do, that IMO maximizes the gameplaying experience while keeping most characters at an easy experience track:
All 6 Humans: Fighter, Rogue, Bard, Gadgeteer(easiest to level), Ranger, Bishop. The Fighter and Rogue would be up front, doing the melee with their Berserk and Backstab abilities. The Ranger on one flank with a sword and shield, or maybe mace and shield, getting his ranged kills and scouting for free for the party. The Bard, and possibly Gadgeteer, could be on the other flank, with a sword and shield, practicing their melee, ranged attacks, and Music and Engineering.
The Bishop, as the weakest, would be in the center, lashing her Bullwhip to practice Mace and Flail, and maybe slinging stones for ranged, for a KO chance, and of course, using her magic a lot for practice.
I wonder if I should go 2 Bishop, and drop one of my characters. Using more than 1 Bishop, you would have to decide which books to focus on. Usually with my Bishop(s), I would let the rest of the party carry me to Arnika, only picking Heal Wounds and Mind Stab(no book for that one) at level 1. Once at Arnika, I would buy every spellbook from Anna and Braffit that I could, and then beeline to Trynton for the +5 Int at the fountain, and see Fuzzfas for his limited spellbooks. Then on to Crock for his level 4 books, and Sadok is close by for his books. Hopefully someone cast a portal and I can go back to Arnika and then north to visit Kunar for his books. I usually end up using spell picks for level 5-7 spells(except Banish, which can be bought or found), because getting to Ferro is such a pain that usually by the time I approach the Rapax Rift, I've already leveled into my 20s and don't need Ferro's spellbooks. That would seem like a process to get 2, or even 3, Bishops in your case, all the spells possible.
As a minor side note, I wonder if it's possible to get the Savant Orb at the Tower to drop 2 Holy Water spellbooks, one for each Bishop, as his drop might pick it twice? It's not a big deal either way. If I do go with 2 Bishops, perhaps one can go for the Staff of Doom, and the other Mace and Flail(Mauler, Diamond Eyes or Vampire Chain). Staff and Wand doesn't seem ideal for the other, tougher characters, as they have so many other options.
I kind of agree with you on Piety being mediocre. It's just that, it's a controlling attribute for every realm and Divinity. While I don't consider it that important, it is worth mentioning. Perhaps I should max Speed first, and get Intelligence to 95 before hitting the Trynton Fountain, then Senses and Vitality for more survivability. Then Piety, Dexterity and Strength last, as I found that my old Bishop was hitting enemies just fine with the SOD, with her skill points allocated properly, 45 Strength and 55 Dexterity.

I've been ironing out my party all day today. I want to make an improvement on my old MDP, who wasted skill points on every realm despite some being almost useless. Here is what I came up with:
6 Humans. Items in parenthesis are what the party is going for at the endgame.
Fighter: Strength and Dexterity, Speed and Senses, Vitality Piety and Intelligence. Close Combat, Ranged Combat, Dual Weapons, Swords(only to start), Mace and Flail(Mauler and Diamond Eyes), Bow(Strong Bow or Siege Arbalest).
Rogue: Strength and Dexterity, Speed and Senses, Vitality Piety and Intelligence. Close Combat, Ranged Combat, Dual Weapons, Sword(Light Sword), Dagger(Stiletto), Bow(Strong Bow or Siege Arbalest), Stealth.
Bard: Strength and Dexterity, Speed and Senses, Vitality Piety and Intelligence. Close Combat, Ranged Combat, Communication, Sword(Light Sword), Shield(Light Shield), Bow(Strong Bow or Siege Arbalest), Music.
Gadgeteer: Strength and Dexterity, Speed and Senses, Vitality Piety and Intelligence. Close Combat, Ranged Combat, Engineering, Sword(Light Sword), Shield(Light Shield), Bow(Strong Bow or Siege Arbalest), Locks and Traps.
Bishop #1: Intelligence and Speed, Senses and Piety, Vitality Dexterity and Strength. Close Combat, Ranged Combat, Artifacts, Wizardry, Divinity, Realm Skills, Mace and Flail(Vampire Chain), Shield(Light Shield), Throwing and Sling(Wrist Rocket).
Bishop #2: Intelligence and Speed, Senses and Piety, Vitality Dexterity and Strength. Close Combat, Ranged Combat, Mythology, Alchemy, Psionics, Realm Skills, Mace and Flail(Cat O' Nine Tails), Shield(Light Shield), Throwing and Sling(Wrist Rocket).
The rationale behind choosing Humans is, as you know, that they get the most precious attribute points total. Nothing is ever less than 45. There are no weaknesses. They can do decent in any profession. Provided you're patient enough, they can get 4 expert skills, by level 30, before the endgame.
I went out of my way this time to avoid any cursed weapons that would prevent ranged attacks. I'm trying to create a party that is flexible, can attack from any range, and has the power to do well in melee combat as well.
Also, with 2 Bishops, both Soul and Element Shield can be cast in Round 1 of combat. One Bishop will do Wizardry and Divinity, and the other Bishop will do Alchemy and Psionics. This will allow for all spells in the game to be cast. The Bishops may have to be carried to Arnika, as I'm not going to pick too many spells right away, maybe only the buff spells that help the whole party.
The Fighter and Rogue will be on the frontlines dual wielding without shields, relying on potions and weak magic at the beginning for healing. Both Berserk and Backstabbing make it so that dual wielding makes a lot of sense, and I feel that a shield will hold back a lot of damage potential. Especially in the Rogue's case, as he learns Stealth, a shield, and Vitality even, become less important over time, as he will be ignored more and more. The Fighter's high HP and heavy armor will make up for his lack of a shield. Also, the Fighter can be buffed with Superman, Body of Stone, Guardian Angel, etc, making him a real tank. Both will get Bows/Crossbows to attack from range.
The Bard and Gadgeteer will each take a flank, using a sword and shield. I don't feel that their melee damage potential is nearly as high as the first 2, so dual wielding seems like quite a stretch with all the penalties involved. It's better to go for the defensive capabilities someone on the flank should have, by equipping a shield, especially the *Light* *Shield*. Bows and Crossbows will be used to attack from range, as well as Music and Engineering.
The two Bishops will stay protected in the center, as the most squishy of the party. They will use the Bullwhip for an extended range attack, while training the Mace and Flail skill. A shield will help them defensively, as they need all the AC they can get. They will be using slings to attack from range, as well as their vast array of magic spells. Eventually, both Bishops will branch out into all 4 spellbooks, to take full advantage of their class, especially considering the heavy experience level penalties. They will probably be a level or two, or three later on, behind the easy leveling specialists.

Worth noting that the Hammer exists, and is a great offhand weapon before you get the Diamond Eyes. Even better, it boosts Mace & Flail, so if you put a mace in your main hand, it will boost that as well.

(It might even make sense to use the Diamond Eyes in the main hand and the Hammer in the off hand until you get The Mauler, as there's not that many maces that can compete with the Diamond Eyes damage wise.)

Edit: Also, keep in mind that the Strong Bow requires 85 STR, so if you have 100 base STR and are hexed, the weapon will be unequipped, which can get annoying. (You can fix this by giving the character an ankh to boost their STR.)
Light Sword is way too rare to include it in your plan. What weapon do you plan on using if you can't get the Light Sword?

(I don't consider any item that has no set location and can't be bought in my party setup, except for the Cane of Corpus with its rather high drop rate. I also don't consider any setup that requires a drop from a friendly NPC (though I may make an exception for Don Barlone).)

Again, I wouldn't rely on getting Light Sword and Shield. I would definitely not count on being able to get more than one of either.

Given your playing style of leveling up heavily without progressing through the game, I would reconsider these two classes, as they fall behind in usefulness compared to conventional casters if you aren't finding new instruments and gadgets.

Again, don't count on being able to get those Light Shields.

Also, I note that your long duration spells will all fall on the same character. Is that OK with you? (With that said, Alchemy and Psionics do complement each other well, allowing you to get decent attack spells of every realm except Devine.)

I would suggest reconsidering Piety; that stat has very little effect later in the game, and your build does not involve getting it early on when it would actually matter. Better to boost Vitality at that point (even though you really don't need the HP at that point in the game).

From a fun stand point, it might make sense to diversify your setups, rather than have both take the exact same stat order.
I think it makes sense not to use a shield with these classes, particularly since the Rogue won't be targeted as much.

(With that said, one could justify using a shield early game before Stealth has had a chance to build up.)

From doing some build crafting, I've found that Humans are most useful for builds that actually need a lot of stats, like if you want a Bishop with more HP than the elven one, or if you're going to attempt to put a Bishop in the front row. For more focused builds, those that need a particular stat high, it may help to use a different race instead. For example:
* For Fighters, there's the standard choice of Lizardmen, who can get Iron Skin really early (except that they don't need it), and Power Strike early as well, but at the cost of being weak against mental magic. Or you could go with Mook, sacrificing SPD and PIE in favor of some nice resistances (not as likely to go insane) and the ability to use the Giant Sword.
* I haven't studied Rogue to see what race works best here (though Lizardman gets Power Strike at 12). (With that said, I think that, even without as many points put in that skill, Rogue might be better than Gadgeteer for Locks & Traps, thanks to the primary skill bonus and the ability to equip the Thief's Dagger for an extra +10 bonus (along with a Thief's Buckler or another Thief's Dagger); note that this weapon is cursed, but you're not using it for combat.
* Casters can get Power Cast sooner in other races. Elf gets both Power Cast and Snake Speed a level sooner than Human (and is why I prefer that race for Bishop, though my current party plan has a Human Bishop as well because that's better for getting Power Strike).
* From my understanding, endgame is closer to level 25 or even lower, except maybe if you're using a small party.

Don't expect to get that shield, and if you do, don't expect to get more than one of them.

Also, worth noting that the Triple Crossbow, due to its high Stamina use, is probably not a good choice for these characters who also need Stamina for casting spells; it might, however, be a good weapon for your Fighter.

Don't forget that there are some shields with other stat bonuses. The Thief's Buckler, in particular, boosts Speed, allowing for faster casting, while the Lithe Buckler boosts Stealth, making the character marginally less likely to be targeted.

The Lithe Buckler also boosts Dexterity, making it a nice choice for some front line builds.
Your party doesn't look like an MDP to me.

It's not really a MDP anymore, more like a balanced party, once everybody is up to speed on their stats, skills, and spells. From what I gathered on the forums, there are 7 Buccaneer Ghosts in the Bayjin Shalllows, each with a chance to drop the Light Sword and Light Shield. Jan-Ette has a small chance to drop the Light Shield in Bayjin. There is a single hut in Bayjin, guarded by a sentry, that has a small chance of containing the Light Sword, but it will take many reloads, as chest contents are set the first time you enter an area.

I feel like it just isn't worth it to try for these items, except maybe the shield from Jan-Ette, but I think I'd rather have the Frontier Phaser, because that seems more interesting to me.

Also, it feels like the Light Shield is so powerful that it could be a game breaker, so I have a self-imposed rule of not using that particular shield.

I did a little research on Rogues, and it looks like Hobbit might be a better choice than Human. You lose some INT and PIE, neither of which is particularly important here, along with 5 STR, but in turn you get 20 more bonus points at character creation. That additional bonus point availability means that you will get better DEX/SPD/SEN, which are important stats, and you can actually start with 1 more STR than as a human because the extra bonus points outweighs the loss of STR.

The Hobbit's stat sum is 310, which is only 5 points behind the Human's, and you get some extra Earth resistance (protects against Crush and Quicksand most notably) as an added bonus (and no penalties).

(Other options, if you're willing to deal with some drawbacks, include Lizardman (but watch out for Insanity/Turncoat), Dracon (gives you a breath attack), and Faerie (Rod of Sprites, if you can acquire one, is the second strongest off hand weapon, and daggers tend to be usable by faeries; also worth noting that armor limitations aren't so bad when you have Stealth).)

Since the Fighter and Rogue dish out a lot of melee damage, I will dual wield with them to take full advantage of Berserk and Backstabbing, no shields to worry about for these two. The Bard and Gadgeteer will have decent armor, so maybe I can justify Light Shields for them. I definitely don't think it's OP for my two Bishops to get Light Shields, as their AC will be a lot lower than the others'.
Regarding the Light Sword, my Fighter and two Bishops will go Mace and Flail, using all 4 good ones: The Mauler, Diamond Eyes, Cat O' Nine Tails, and Vampire Chain, so no swords there. That leaves 3 sword users, the Rogue, Bard, and Gadgeteer. Swords are by far their best weapon choice, no Axe, Mace and Flail, or Polearm skill for them. I have a choice between giving them Light Swords, if I could farm that many, or Fang. According to Flamestryke's site, nobody in my party can use the Ivory Blade or Demonsbane except my Fighter, who is going Mace and Flail for a change. So only 1 of the 3 can use Fang, and the others will have bad swords to use unless they can get the Light Swords.
I wonder if my Rogue should be the one to do Locks and Traps, despite the fact that he has so many skills to work on: Close Combat, Ranged Combat, Dual Weapons, Sword, Dagger, Bow, Stealth already. It might be preferable in the long run, since he gets a bonus to L&T. The Bard and Gadgeteer can also do it, but they get no bonus.

Worth noting that The Mauler is buyable, so it's easy to get one for everyone who can equip one. You could even have 8 characters using this weapon if you really want.

I don't think it's reasonable to plan for multiple Light Shields, simply because that item is so rare; in fact, I think it's a bit much to plan for one (though at least Jan-Ette's drops can easily be re-rolled).

There comes a point where it just isn't fun to farm for rare drops, and Wizardry 8's approach of only giving you one chance to get them doesn't help. (In fact, that's one of my biggest issues with the game.)

My biggest issue with the game is probably the fact that chest contents are set the first time you enter an area. So every 5 character levels can potentially get you better items, but it still isn't guaranteed. According to Flamestryke, the breakpoints are level 1-5, 6-10, 11-15, 16-20, 21-25, 26-30, and 31+. So, for example, entering the Upper Monastery and Arnika Road at level 6 instead of level 5 would get you the next best potential treasures. Entering Arnika at level 11 instead of level 10 would get you even better potential treasures. I don't think anything important is in these areas though.
The question still remains though: Which swords should the Rogue, Bard, and Gadgeteer use? Light Sword(s), Fang, Bloodlust, Diamond Epee, Mercucio's Blade(Bard only), Saint Bastard(sold by Ferro, ok but kind of slow). In Arnika, and maybe for a while, it will probably be: Rogue with Bloodlust(Berserk and Backstabbing can stack), Bard with Mercucio's Blade(provided the rogues drop one), Gadgeteer with Diamond Epee. I would consider these three decent, middle game swords, but I think that I can do better. I've never had a Light Sword or Light Shield before, I don't even think I knew about the Buccaneer Ghosts' drops in 20 years of playing this game.
If I train my Rogue on Locks and Traps, he can naturally get a skill of 75 +25% bonus = 93, the same with my Bard and Communication, and the same with one Bishop and Artifacts. The other Bishop will train Mythology, but everybody will become good at it eventually with all the monster spawns.

I used to do a lot of Mook Rangers, I would always max their Senses for Eagle Eye and Dexterity for Reflextion early, because they both start high. I would then work on Speed for Snakespeed, Vitality for Iron Skin, and Strength for Powerstrike (2 per level). Having all 5 attribute maxed and all 5 expert skills could be done I believe around level 35, about the time when nothing outside of AP would out-level you. I never bothered with Intelligence for Powercast or Piety for Iron Will because those are both caster stats, and the Ranger has a lot of things to work on. As a hybrid, he or she suffers -4 caster levels to the Alchemy spellbook, and Piety is way too low to worry about (I think it starts at 25). Powercast for the Alchemy spellbook is questionable, since there are so many good cloud spells, and Quicksand seemed to do ok for me even without PC. Then again, this was a long time ago, and I was playing on Novice.
Are you sure that you want to start the game as an apprentice? Also, Power Cast and Priest spells don't seem to go together (the only reason I did it on my last Priest was because I was running a MDP). What are the high level Priest attack spells? Lightning, Banish, Lifesteal, Falling Stars, Death Wish. It's up to you really (PC is always nice on a caster, even Priests), but this combination seems stretched rather thin.
This is why I generally don't do hybrids much. They have a lot of attributes and skills to work on, and they get experience penalties compared to specialists and specialist casters. W8 rewards specialization, and working on both might and magic carries heavy penalties.
Speaking of that, do you think Bishops are worth the elite experience penalty, the worst in the game? I believe that they definitely shouldn't be one spellbook, or else make a specialist caster. Working on two spellbooks at a time, if you don't power-train, seems to be a good balance. At some point, once mastery of those two spellbooks is attained, I believe that all four spellbooks should be worked on, to justify their considerable penalties.