I've got a MY05 CGM WRX Wagon, and am looking at getting the Prodrive P1 17x7 wheels. I've never bought new wheels before so I'm a little confused on sizing etc. I tried reading through tire rack articles, and I couldn't find anything to tell me what that 7 was in the 17x7. I'm assuming it's width, and I know the stock wheels are 16x6.5. How do I translate that 17x7 into a tire size that will fit the wheel? I was going to get some "Bridgestone Potenza RE050A Pole Position with UNI-T" from the tire rack, but what size? Would 205/50ZR17 fit?