The waggy axle will be too narrow, it is >2" narrower than the rear. The best bet would be a FJ80 axle or a Fullwidth d44 (preferebly narrowed to ~64-65"). A 2gen 12bolt should bolt in, I am not sure on the abs sensors, though. My 99 had two, one on each end. My 96 has one mounted on the ring gear.

Here are two websites to check out for link ideas:
http://www.houlster.com/amigo/SAS/
http://actionjackson.com/cruiser/mods/20060110.asp

Not being able to do the work yourself will be a major factor in driving up the cost.

'99 Trooper 3.5L->R150F->Duals->4.7->60/14b->38.5s
'96 Trooper DD