This is my planned party:

1 Bard, drow
2 halforc barbarian, fighter
3 aasimar paladin of Ilmater/few levels of cleric
4 rogue/transmuter
5 druid
6 sorcerer

Please, share you thoughts.

I made a similar pary.
I personally prefer wizards over sorcerers, and my paladin was a Helmite with three levels of fighter.
Imo drows are not really worth it because their leveling up is unbelievably slow, they are 2 or 3 levels behind the others.

Bard's would be something like back up sorcerer, so I took it for roleplaying reasons.

That party covers healing, rogue skills, tanking, and arcane. It should be fine.

Using the drow race will hurt the bard's number of levels some, since drow have an Effective Character Level (ECL) to make up for all the special powers the race possesses, but the party should be fine.

Why are you adding a few levels of cleric to the paladin? I'm unclear what you are looking to add by splashing cleric into a paladin main. The other way around makes sense to me, splashing a level or two of paladin into a cleric build, but a few levels of cleric doesn't seem like it would add much to a paladin build. Being about 3 levels behind (over time) is intended, to make up for all the special abilities the drow race provides a character. Iirc, the aasimar should end up one level behind for simliar reasons.

I know, and I think that while 1 level behind for Aasimar is an acceptable tradeoff, 3 for Drow is too much unless you are playing on easy.
Just a personal opinion! :)
Granted, I played both entries in the series at max difficulty.

Also, in IWD bards are more powerful than it seems. Their songs are very useful, and the War Chant of Sith is of incredible help in 2.
In the first one was imo overpowered, you had very fast regeneration and higher armor class, basically becoming unbeatable.

I tend to agree. I was basically just confirming what you said, and providing the reason why it is like that (in case (generic) you happened to be unaware of the reason why). :)

Your party will work fine.

1. The 2 level Drow ECL penalty for the bard shouldn't be a problem, because of the extra XP at the start (s)he'll reach level 2 at the same time as the others, you'll have to wait a bit longer to get the powerful level 5 and 11 songs but at the end (s)he'll be able to sing in perfection.
I'd dump wisdom to 3-4.

2. If you haven't played the game before consider keeping the half-orc a pure barbarian since you don't know which weapons you'll find during the game while greater rage and barbarian damage resistance are powerful independent of them. Far more important than level distribution is maxing out strength, I'd also max dex and con.

3. Make sure to max strength for your paladin.

1) Save levels of Fighter for your Barbarian after they get 20 levels of Barbarian, and the most you may want is 4 levels for Weapon Specialization and (if you're aiming for such) Maximized Attacks.

2) Have your Bard, Rogue/Transmuter and your Sorcerer cover spells that the other can't. For example, your Sorcerer could deal primarily with offensive spells while your Rogue/Transmuter deals with buffing/debuffing and/or summoning. I don't have the manual in front of me, so I don't remember offhand what school of magic is forbidden for Transmuters.

3) As said before, have your Paladin focus more on levels in Painbearer of Ilmater. They will have buff spells any of your other characters won't. I don't know what spells you plan on using with your Druid or Bard, but they can definitely ease the burden of healing in the regular mode for the game. Just remember that you'll primarily be using Heal and Mass Heal to restore HP once you get into Heart of Fury mode.

4) What races were you planning to use for your Rogue/Transmuter, Sorcerer and Druid?

That is a ridiculously OP party. Nice setup.

Drows are good if you basically don't want to level. LOL. b/c they're op from the start.

Keep in mind that a Drow will drag down your party exp share, making your group level slower overall.

But with all the high exp classes and multiclassing going on here you're pretty much going to be op from start to finish but fall pretty short of max level for every character.

Classing paladins and clerics is a good call. IMO, paladins don't have to level past lv 4 or 5. They pretty much stop gaining useful abilities after that. Classing them with clerics gets them more and better divine spells and better turning. Aasimar are the quintessential paladins.

Barbarian/fighter is a classic combo. halforcs are the quintessential barbarians.

classing rogue with anything is a good call. Wizards are the natural choice.

PROTIP: Make your druid an orc. Pump up their STR to max and just give em a stick and they become an unstoppable murder machine.

FURTHERMORE, classing druid/barbarian is insane just saying.

Sorcerer? meh. I prefer wizards. I guess I just never got sorcerers. Sorcerers come off to me as wizards for newbies who don't want to fuss with memorizing all their spells per day. Sorcerers are easy to mess up so make sure you claim all the right spells at level up.

It's worth noting that (some of this could be considered exploits):
* If you don't level, you will get more XP from enemies; this bonus may be significant to unbalance the game once you *do* level, so you might not want to take advantage of this.
* If you don't level up your Drow, but do level up everyone else, the entire party, not just your Drow, will get more XP. (One possible strategy is to level up a Bard to level 11 to get all the songs (or stop at level 5 for the luck song), then don't level them up for the rest of the game. (Again, this can unbalance the game.)
* If you introduce a new character later on, or if you replace an old character with a new level 1 character, your entire party will get more XP, which again may make the game too easy. (I actually would recommend cheating the new character up to the level of the rest of your party in order to keep the game from becoming too easy.)

In any case, I consider the XP distribution in Icewind Dale 2 (and in D&D 3.0) to be rather unsound, given how it's quite easily broken (especially the last point I made above, where doing something reasonable (and that didn't cause issues in IWD1) can break the game); it doesn't help that the game doesn't implement the D&D rule against double leveling. (Temple of Elemental Evil uses 3.5 rules, where each character uses their own level (not party average level) to determine XP gains, and implements the rule against double leveling, preventing things from getting too ridiculous. The Gold Box games implement the rule against double leveling, but with 1e XP distribution (player level doesn't affect XP gained) and sometimes not being able to train for a while, the rule does more harm than good there.) Sorcerers are actually good in IWD2 (and in IWD:EE) because of a few characteristics of these games:
* Wizards, for whatever reason, do not get to choose spells at level up. I have no idea why they chose to do this, but I don't think this is the right decision from a game design perspective (and it clashes with the tabletop rules). As a result, a Wizard can only get a spell if you can find a scroll of it. Sorcerers don't have this limitation, since they *do* get to learn spells by level up.
* Scrolls are scarce. You might get access to new spell levels without scrolls for them (especially if you abuse the XP distribution rules to get more XP than intended), and if you have multiple Wizards (or, in IWD1, Bards) you might not have enough scrolls to go around for the more important spells. (IWD1, for example, has only one Stoneskin scroll per playthrough, I believel.) Sorcerers can, of course, learn higher level spells as soon as they reach the minimum level required to cast them. Note that this is in contrast to the Baldur's Gate series, where there are plenty of scrolls to go around (though some scrolls, like Remove Magic, are still scarce).

Note that Clerics and Druids aren't affected by scroll scarcity, since they automatically learn all their spells; in IWD2 Bards aren't affected either, because they learn spells like Sorcerers do.