[Gimli]

Well since you are looking for defense first, for the Monk you want to go with Wis and Dex for AC (Deep Gnome also gets another +4 racial bonus). Wis I would say should be the higest stat as you can't buff it like you can Dex via Cat's Grace. If you went with an Illusionist->Monk, you would also have a high enough Int (13 is perfect since it sounds like you want to be able to cast up to level 3 spells) to take Expertise and could really have an amazing AC (and AFAIK your mirror images all have the same AC that you do, which then helps them last that much longer). Also you'd get some extra skill points that way which might come in handy, and the free racial mirror image, blur, and invisibility abilities thrown in. I would go Wis, then Dex and a 13 Int first, then worry about Con/Str; Cha could be dropped as low as possible.

The Monk/Sorc would allow you to switch back and forth if you decided you needed to later in the game (disclaimer: I don't play HoF) and get some extra spells per level (altho not tons more than an Illusionist with the extra racial spells the deep gnome gets), but then you'd have to drop Int as low as possible, not be able to take expertise, and not have the skill points to work with. I think the Deep Gnome build is "better" but either could work for what you're looking for. Warning tho, both would "nerf" martial arts somewhat as if you get even +1 to your BAB from a class other than Monk the game gets confused and no longer applies the special Monk MA/BAB table properly (might be a mod that fixes that?). Also part of the "ease of use" mod lets you use Weapon Finesse with fists so the average Str score could be mitigated somewhat. And you'd still have the stunning attacks (and a harder to resist quivering palm thanks to the high Wis).

Pally/Wizard is very demanding stat-wise; I really think going Sorc->Pally has much more stat synergy and would reccomend going that way instead. Max Cha obviosly. Unless you are going to cast without armor on and then switch to the inventory screen and then don armor, you will also need a high Dex (otherwise you can go for the heavier armors and only really need about a 12 Dex to still get the best AC you can that way, and with Cat's Grace, an 8 or 9 Dex would do). Then I would say Str/Con are about equally important and Int not at all. Wis can also be dropped pretty low as the high Cha will make up for the will save penalty.