I agree I dont see many 4wd either and the ones I do are hammered.
If I was to build a 4wd I would probably want to start with a 2wd anyway, Good excuss to 4 link the back with coils. Use the mounting points from the trailing arms for lower bars add a crossmember for uppers and wahlah reverse triangulated 4 link with coils and the front leafs are easy to fab up but id probably do coil there too, it would ride nice and flex like no other c10, but if your looking for original then a 4wd truck is the only way to go.