The trouble there will be finding anything in a 17 or 18 that will have the current rear backspacing. Personally, I'd swap out the rear knuckles from an 88-96...but I'm not sure what all is involved with that. I know the parking brake is completely different, and I think you could reuse everything else. But if it's that easy, it seems more people would do it.
The best place I know of locally for used Corvette Parts is the
The Corvette Shop on Dale Mabry in Tampa.