IMO, If you plan on doing this over time, just don't do it and sell it in a couple of years and buy a 07-09 gt500. I have modded my 2009 gt to look good and run good (high 12's with slicks). I plan on selling the car after a couple years of playing around and then move up to a gt500. With a gt500, you could do a blower at the same cost it would be on a gt, except you would get 700 hp, not 500 hp.
Just my 0.02