I would really recomend going 2wd (dana 80 )paired to 3.73 for ease of swap, minimal fabrication and ease of access to parts on the secondhand market.
you should check out www.searchtempest.com
and get the number of the guy up in wolcott vermont who has all the stuff you require.
I think also that with 2wd it increases the longevity of the vehicle, saves you on fuel, increases handling. right off the rip you're 4 inches lower for better handling. and can still hall 3500 lbs in your bed FACT.
Good luck buddy