Well if you want wide then new wheels are the best bet. Stock 17X8s can safely mount a 255/40 and if you feel like pushing it then you could try a 274/40. 275/55 is absolutely ridiculous though. That would be a gigantic sidewall. Or you can try some spacers to help kick the wheels out further. I just went with new wheels and some 315s.
Sold - Black 2000 Mustang GT, gone but definitely not forgotten
- Silver 2007 Corvette
Current - DHG 2001 Bullitt