Been a bunch of years but I bought some 17x8 wheels for a '97 GT and spent $90 in total for all 4. They don't match (different color in the spokes) but most people don't notice. You would have to open up the center a little and might have to run a 1/4" spacer and longer wheel studs but other than that they should bolt on.
Get some decent 245/45R17's and you should be good.
Sorry I can't help with an actual set of wheels but I would watch CL and MP for a set of wheels of a '95-04 Mustang GT. Look for a 17x8 +30 wheel.
Oh, you might need a wider rear axle too. Forgot about that.