I feel like the suspension would be the only difficult thing to pull off depending on what that means to you. Even still custom 4x4 suspensions are done all the time.
The rest of the stuff has been done in varying levels of popularity.
If it were me and I had all the time and money in the world...
LS7, 6L80e, 1 ton axles (D60 + 14 bolt) w/ discs, coilover suspension, then go wild with the dual zone AC or lightbars or whatever else trick you want to throw at it
