They do a little of everything. I surmise there isn't enough guys out there with the $$ to pay someone else to swap Gen III small blocks into 4x4 trucks so they diversify. They will do most anything from a harness to a turn key setup. Life ain't cheap and neither is their stuff...but it's good quality. I looked into the Gen III and I would have to say it's a good way to go in terms of bang for the buck. Personally, I decided on a diesel but it's really just matter of whatcha want.
I agree, they need some more 4by stuff on the website. Perhaps they are busy enough without it?