Wheels for a 190E 2.3L 8V

I need to know what is the BIGGEST wheels I can use on my car, I am willing to do all modifications necessary, and will upgrade my whole suspension to handle the extra stress that 20" rims (if they would fit, that's the biggest I want to go) might expose it to. I want to do this for looks only, but of course safety is my primary consideration. Performance is secondary for now. Will anyone tell me if 20's will fit if I install the the EVO II kit with EVO I fenders (a great looking hybrid kit!). Thanks to everyone for you pending replies!