scholtmj - We got the ZR1 for 10k locally. Not a great deal, but not too bad either considering it's got a "warranty" against mechanical failure.
You're correct, it's sitting on angle iron drilled out to the bolt pattern. It's simple, mobile, and we can set the ride hight to wherever we want.
Here is a couple pictures of the rear suspension/frame. It will be made beautiful when we take it back apart.