Mike,
I'd only be guessing, because you have GTS fender flares and I'm really only familiar with the dimensions that work on a stock bodied Pantera. Dennis Quella told me, with aftermarket GTS flares, you can add about 1-3/8" to the outer dimension. Another vendor with GTS flare expertise is Ron McCall. I have photos (below) of a GTS bodied Pantera he built and the dish on the rear wheels was HUGE! I'd send him a PM. Looks like you have the same wheels. Perhaps yours could be "re-rimmed". Also, why only 8" and 12" wide? You could go an inch wider, front and back, without difficulty. What tire sizes will you be using?
