I would really have to say Dwarven Defender. The thing is dang near IMPOSSIBLE to kill if played right, but I don't know about the whole paladin thing. I would just go with fighter until you qualify for Dwarven Defender, then just continue to advance Dwarven Defender past the 10 levels in the DMG (yes, you can do that - it's written in there somewhere). Whenever you want a new feat or two, just take another level in fighter. By taking levels in Dwarven Defender instead of paladin, you get a bigger hit dice, better damage reduction, more Defensive Stances, etc. etc. True, you lose some healing ability and such, but with more DR, healing enters into it less and less. Just have your cleric focus healing on you, since you should be taking the most damage, and boom - you're a freaking tank.
On the issue of firepower, just be stereotypical dwarf and put a good score into Str with a dwarven waraxe. 1d10 damage, x3 critical, and the ability to use a tower shield with that? As a MARTIAL weapon? Priceless. For damage, just take Power Attack and Cleave. With Defensive Stance, you won't be moving much, so you might as well cut 'em down as they close in. Screw accuracy, I'd want to take crazy damage and deal crazy damage. Ooh, and since you'll need Endurance for Dwarven Defender anyway, you might as well take Diehard. THEN you'll be impossible to kill, but I just personally like the idea behind Diehard more than the feat itself.
If you want to send your AC into the ionosphere (that's REALLY high), take the Combat Expertise and get a Dwarven Waraxe of Defending. Of course, that might be overkill. Of course, Combat Expertise implies putting a 13 into Int, I think, so it's really your call. Come to think of it, while Combat Expertise is a good feat, you really have no use for Improved Disarm, Feint, or Trip, and I seriously doubt that you'll be putting much into Dex, so Whirlwind Attack is out. Your choice.
So yeah, I'd say just go for a dwarf fighter/dwarven defender (more defender than fighter); statwise, I'd reccommend medium-high Str, low Dex, very high Con, Int and Wis are up to you, and dump Cha. For feats, use what you like from the above reccommendations, but consider Improved Bull Rush and Overrun. That's just to complete the tank image.
