it should look pretty decent. i would go with a 225/40/18 tire but if you want some more meat than just get the 235's. and yes wheel dude is the best deal unless you want to buy them used.
as far as mods go i would get coilovers first or youll regret them not fitting and rubbing like crazy. get some bc coils and then get the wheels. as far as fender mods if you want to go slammed you will need all 4 fenders rolled and rears slightly pulled. also youll probably have to pull you front fender liners and tuck your wiring harness. i had to do all this plus use a torch and hammer to smash in my front fender wells to make my 18x10 +25 fit on my wrx and im running 225/40 tires with -3.5 front camber and -4.5 rear. but im also maxed out on how low i am.