Hi Steve,
I own an SPF MKIII. When I bought the MKIII I strongly considered the SPF Coupe. I emailed with Peter Brock a number of times and finally went for the MKIII just because I had always wanted a Cobra Roadster. I think Brock's SPF Coupe is outstanding. First, it is a high quality build by Hi-Tech in South Africa. Second, it is a second iteration of the original by the original designer himself, Pete Brock. As for the engine and transmission installation, that will depend upon who and what you choose. My recommendation would be Roush all the way with one of their 427R engines. When you are finished you will have about 120-130 in the car. I wouldn't trade my GT for it, but if I had the extra cash, it would be in my garage. Incidentally, I have nothing but positive comments about working with the SPF dealership in Ross, Ohio, Dynamic Motorsports. Good luck with your decision.