besides the info you asked me for in PM (why did you PM me if you were posting this?), I'd urge you to first pick a TIRE size and THEN pick a RIM size. If you pick 225/40/18 or 225/45/17, you really don't need an 8.5" rim. 7.5" or 8.0" will do just fine and you'll want as close to stock offset as you can find. If you pick something else, it gets more complicated and I recommend against it but each to their own.
You can fit 325 wides on there if you really feel like it. Just go with, say, a 17x11" rim at +0 offset and say, a 325/30/17 tire (good luck finding that). Will it help your handling? No, I would say not. The suspension generally doesn't react well to the wheel center being a full 2 inches from where it expects. Also it's very dangerous (they'll be sticking out so far you'll be partially "open wheel" racing) and illegal.
Course, a wide body kit replaces the suspension and widens the fenders facilitating those big meats. There are actually subarus out there with 325 wides. Gotta pay to play
