It would be better to supercharge. Honestly I don't believe any of the aftermarket turbo kits are anywhere near as good as the aftermarket SC kits. I know I am biased but I have built both and a V8 with a mild boost supercharger is as reliable and easy to live with as a stock engine yet will be making 550 at the rear wheels easy.
2010 GTRR in 5.0 Magazine [http://www.mustangandfords.com/featured-vehicles/m5lp-1212-2010-ford-mustang-gt-rr-total-fabrication/viewall.html]
2015 White SC, PP, etc....