I agree with a S/C build you can work your way well into the 13's or into the 12's with slicks. My car is a very basic build, but I don't launch the car at the track and my 13.01 was on a 2.4 60'. If I were to launch on a slick (trans holding, lol) I could imagine it could drop 6-8 tenths without much trouble.
Hate to say it, but I am a roll racer at heart and enjoy sticking with LS cars who run a solid second faster than me at the track while on the street. If your looking for shock and awe with your car then IMHO a turbo is the way to go. Opening that cutout and surprising nice cars can never get old.
Everything boils down to what your looking for. The first thing I tell people who ask me about a turbo GP as a daily is you should have another car you can count on. In my experience a turbo car can be temperamental sometimes.