Well, I have/had a lowered fox and I have Cobra R's (17x9) so your in luck
I'm running 245-45-17 on all four. Any bigger in the front, you'll get rubbing. When my car was lowered, I had to roll the fender lips inside just a little bit. I used a small hammer and curled them myself. When ever I hit a large bump, the tire would go up in the wheel well and rub on the lip

The rears are fine. I didn't have to do any modifications to it. I raised my car back up to stock height for drag racing reasons. Also, keep this in mind.... If your running 2" or bigger drop, AND and alunium drive shaft... the drive shaft will rub on the tunnel. Ran into that problem as well
