We love the Bridgestone Potenza RE-750 and have them on both GTs - awesome wet or dry traction, zero noise, excellent wear. $165.00 at
www.tirerack.com.
Our other option was the Goodyear Eagle F1 GS-D3 @ $183.00.
With tires, you truly get what you pay for. Check out both these tires at
www.tirerack.com and look at the survey results on the overview link (for each tire). The tires are rated, on a scale of 1 to 10, for their wet traction, dry traction, hydro resistance, snow traction, cornering stability, steering response, ride comfort, noise comfort and tread wear. Compare these tires to others and you'll see why they cost a few bucks more...
I'd stay with the 245-45/17 on the 8" rim. You could put something a little wider in the back, but then your ability to rotate them just went out the window (and wider tires up front are just a pain). With good tires like these, you'll hook much better than with the OEM Goodyears anyway.
Best of Luck!