I didn't check sizes for the GS but for street tires (i.e. work in the rain and last at least 12k miles) I'd look at:
Michlien PS 2
Nitto NT-05 or maybe the Invos for the fronts and 05s on the rear.
A forum community dedicated to Chevy Corvette owners and enthusiasts. Come join the discussion about performance, modifications, racing, restoration, classifieds, troubleshooting, maintenance, and more!