Best bang for the buck: 17X8 & 225/45-17.
Tread width-wise, the wider tires aren't really wider (click on the specs tab:
http://www.tirerack.com/tires/tires....ot+Super+Sport), but they certainly cost more. The tread width of 8.2" is plenty for a car with your car's power, and will serve you well until you're north of 200 RWHP.
A general rule of thumb for performance is to keep the tire's tread width within +/- 1" of the wheel width. In that 2" range, if you have a choice, a wider wheel with a narrower tire will provide more performance.