search around the internet for a Tire Calculator (i forgot the real name), it will tell you what size of tire you should get so ur speedometer won't be off if you change to different sizes.
Wider tires(225's) would make the car look better. But as someone already mentioned, you will need a wider rim (7.5-8"

. The rim size (16", 17", 18"

doesn't really matter with the 225 or 215 issue. You will have to use one of the online tire calculators to find out the exact measurements you'll require.
I'm new here, so I dunno what'll cause rubbing, but I know that i wouldn't think about touching anything with the suspension on this car because its just amazing, i woudln't want to mess it up.