I think color coating the rims you have now is a good one. I wonna take the opportunity to post the pic of my favorite corolla. I love this one... so clean! These are 18s. Sorry I couldn't post a bigger pic, this is the only pic I have of this car. Check it out.
Yes, i'm talking about color coating stock rims. You can go with 19s but then your ride with be very rough and will slow your car like crazy. I'd stick with 17s or 18s if I were you. I"m selling brand new RSL Elities if you're interested.