Hi Ralph,
Welcome to the forum. My thought is that you can convert a reg cab to a 5 window cab, but why? If you are hung up on a 5 window cab, that's all you should be looking at (as I think the fabrication and trouble would not be worth the hassle and extra $$$) OR if you find an 'EXCEPTIONAL' reg cab, you might be able to find a 5 window cab only and go that route?
Anyway, let us know what you come up with. I think there are plenty of folks that can help you out from the SE part of the coutry.
