dodge truck questions

I would like to build myself a nice rig to be a daily driver/hauler/4 wheeler. I have a few questions before I go looking. How swapable are bodys and chassis late 70's to late 80's? I am here in Wisconsin so all the 4x4's I have found so far the bodies are crap. I have found a couple of 2 wheel drive trucks with decent enough bodies. I would like to maybe find a magnum 5.9 that is fuel injected build up it up some. I have built several carbuerated 360's but I have no expeience with fuel injection. Is that something a hobbiest like me could do easy enough? Would it be best to get a 3/4 ton chassis with dana's or would a 1/2 ton with 9 1/4's be good enough for what I need? I won't be doing and seroius pulling or any hard core off roading. I am just looking for a nice rig to do a little bit of everything. Also are after market rims just as easy to get for either axel?