Defboy, Any passenger drop diff will work, but keep in mind there are going to be A LOT variables ie:
Custom driveshafts
link geometry
steering geometry
Gears
Etc, Etc, Etc...

I used a Dana 44 because it's been done before by Dave, his came out of a wagoneer mine came out of a scout. I'm going to have to replace the steering knuckles with a chevy or jeep to do a high steering set up. There is a lot to this project, reaserch, reaserch, reaserch before you jump in. Make sure you really want to do this, because even with my simple setup I'm still going to be out of commission for at least 2-3weeks while building.

Kiarazy- I'm going with leafs int he front and a 1/4 eliptic in the rear. Leafs havent been done on a Kia yet but from the professionals I've spoken to they will most definatly be the cheapest and the easiest to fab up. ROKIA here in Reno Has already done a 1/4 eliptic rear I will just be using stronger springs to give a firmer ride. here's an example of ROKIA's eliptic suspension: