This build is not very complex and maybe even obvious, but in case you overlooked it, I post it here.
Pros:
Good build for the main character, especially if you want to replace Valerie. You will be more tanky than Valerie and way-way more damaging. Plus, your party will benefit from Tactical leader's abilities (Battle Acumen finally works!).
Cons:
There is a few very significant self-buffs you will have to use repeatedly. It's a bit annoying.

Race: Not important. I prefer Human, since they have an extra feat.
Build: 1 Fighter, 2-17 Tactiacal Leader, 18 Fighter
Make sure you have 13 DEX and 13 INT and at least 14 WIS. STR is the most important stat, but I think that 18 is good enough, so we have some points to spend into CON too.
The key point of this build is Domain of Luck. It's very broken. You roll twice every time and choose the best result. Inquisitor for some reason gets class bonuses for both will and fortitude saving throws, with Bit Of Luck your inquisitor will be almost as much protected as Jaethal to negative effects. Plus, with an Estoc most of your hits will be crits. Since Inquisitor also has bonus to critical hit confirmation, they almost never fail.
Feats:
At first I suggest to take all those feats that improve your AC: dodge, armor/shield focus, combat expertise. Once you have those, take exotic weapon proficiency - Estoc. At lvl 11 you will access Improved Cricical (Estoc). At Inquisitor lvl 13 you may take Cricical Focus to access Sickening Critical at lvl 15, but I don't think it's the only way. You may pick whatever you want at this point. Probably, Metamagic: Extended Spell is a good idea, just for your comfort, since Divine Favor and Power wears off very quickly.
Important Teamwork feats: Outflank, Shield Wall.
Important spells: Divine Favor, Divine Power, Magical Vestment, Righteous Might, Heal.

Summary:
It's not too hard of a task to generate a character that would have the highest AC. The problem for me was that I wanted him to deal at least some damage or have some utility. This build is definitely a lucky find for me. This char does have the highest AC, but his damage and utility are also on top. Basically, he's got everything at once. I hope you'll enjoy it.

doesn't look tanky to me at all. it won't even get 70AC by himself and his touch AC is abysmal. Not sure about buffed AC either, but legendary proportions and a lot of gear can fix most anything. although I don't think it will have 70/50 AC to be counted as a tank I also Don't see where the damage is supposed to come from. as far as I see it hardly has any damage boosts.

He is as tanky as a heavy armor user can be. 70AC is accessible with Gyronna Amulet, else it's 65 at best. 50 touch is not accessible, obviously, just like for any STR-based hero. I agree that it's kind of a weak point, but touch attacks usually are not very damaging and can be outhealed.
Damage comes from critical hits, obviously. Crit chance is 51% for his first three attacks, each one deals around 120-130 on crits and 45-50 (taking into account -15 damage reduction) on hits, the forth attack has 36% chance to be critical.
Rougly speaking it's about 200 damage per round. It's not like crazy damage, but it's not a pure dd or pure tank, but a pretty damn good combination of them. So those stats look fine to me.

Righteous Might provides pretty much the same bonuses as Eaglesoul and obviously it can't beat Bane Weapon and Judgements with just +2 AC +4 STR. No, I strongly believe that Inq is a much better choice than Cleric in this case. Moreover, Clerics are really good only at high levels, while Inq is quite solid during the whole walkthrough.

eaglesoul is sacred bonus to STR and AC, Divine power is luck bonus to attack and damage. Don't see what they have in common, leave alone the fact that sacred bonuses are hard to come by, especially to stats. And cleric is not only good at higher level. If your cleric can channel negative energy it pretty much crushes early-game with that +2d6 trinket. Sure, enemies can save from it, but it's still boatloads of damage. And even barring that they attack at same BAB that inquisitors do, but have more spells isntead of judgements that you can use once a blue moon to help in one encounter.

Oh! and ifyou want bane weapon - play magus. He will always have bane by endgame instead of counting rounds to uselessness. And more AC and more damage and whatever else you fancy. In case of scion he will have UMD to use all those silly cleric spells should he want to as well.

I don't try to take a dump on the concept here. I just really never saw anything good about inquisitor apart from solo tactics 3 level dip. Whatever you lose for it always is more than what you'd gain.

Yep, I fixed that. Anyway, in my opinion Eaglesouls is certainly not some key spell you'd want to switch to Cleric for.
Channel Negative energy has ridiculously low difficulty check, I dunno if it crushes early game or not, but it surely gets uselss very soon.
I am not very much into theorycrafting, so I will try to avoid the following arguments. If you can improve this build, I'd be interested to see that. I don't mean to be rude but, to be honest, so far this discussion looks quite pointless to me. Yep, that's what you do, you switch from cleric to magus now. I mean, if I respond that magus doesn't have access to Domain of Luck which is the key point, you will switch to something else and it will continue on. It leads nowhere.

well... it can be improved in every way by not being inquisitor. same AB, but not per encounter, same AC, but not per encounter, same damage give or take and all the cleric goodies on top of that. All you technically pay for it is spreading teamwork stuffs, that are not even that good for the most part for like 10 rounds per pop.