Im about to get QA1 shocks and Eibach sportline springs installed on my SS. From experience does anyone know how wide i can go with an 18. I really want to go with the nitto 555's. Plus i can't seem to make my mind up on what rim to go with, I thought i was sold on the Z06's but after looking at several pics, i really like the C6 wheels. Any help would be appre...