Wheels & Tires - largest diameter c5 zo6?

i have 17" c5 zo6's right now but want either 18 or 19s,, does anyone know if they are made in the right offset (i want them as close to the fender lip as possible) or made at all. the only sets i can find other than the standard 17" is the staggered 17/18 that are on ebay.

theres a red lt1 with 20" c5 zo6's, so there should be some 19's roaming around somewhere. 18's are widely available. i have 18x9.5 with a 56mm offset i think, cant rly remember