On the older Amigos the steering is the same between the 4x4 and 4x2.

I beleive the mounting kit was NOT a Rancho brand. I also beleive that I found the info on the Summit Racing site last time I was looking for it.

I would think that a good set of shocks would be more useful on the mostly graded road. Or maybe adding some weight in the back of the Amigo. A couple of bags of sand are always good for keeping the tires on the ground.

Good luck.