The 1990-1992 2.4 SOHC Mighty Max and Ram 50 engines are desireable because they're FI, 6 bolt, very reliable other than their ECUs (which can be fixed easily enough) and they don't have the problematic MCA jets. 2.4 and the R5M21 5 speed transmissions they came with are easy to come by and should bolt in to your truck but I'm not too familiar with 1st Gens so double check.

Any 6x5.5/6x139.7 steel wheels off old Datsuns and Nissans, Toyotas, even Couriers/Sundowners should fit. GM truck wheel swaps are popular too but you maybe have to bore out the hub.

Post pics! Welcome!