Do you want a bolt in or welded one? The autopower doesn't fit well with sunroofs if I recall correctly.
Leo Capaldi does cages for the spec focus and I'm sure they could just do the back half for not much money. I liked his builder because they tie into the B pillar.
I know there is a good custom builder in Akron.
I would have thought you'd have perfected your welding skillz by now and would be doing this yourself.