19's will fit w/out any problems, that is if your running a 35 series tire and the right offset wheel. 20's can be run butyour going to have to do your homework on finding the right wheel with the proper offset. Most companies are making 20's that can be run on FWD cars now in 7.5" widths. I'm running 19's all around with air ride suspension and don't rub at all, I was also running 19's with goldline slammer spring before going to air ride with no problems either.
Kevin