Fran I've heard the Forgeline EV1 18" wheels will clear the CC ZR1 brake system. That's what it says on a few forums, but I've never seen it in person.
http://forums.corvetteforum.com/c6-corvette-zr1/2379309-forgeline-ev1-one-piece-wheels.html
http://forums.corvetteforum.com/c6-corvette-zr1/2379309-forgeline-ev1-one-piece-wheels.html