Did the same upgrade here...and got the entire package and slotted rotors from VB&P. I had the rears powder coated red.
I am jealous yours is on the ground and running. I can't wait to see how they react once I have to nail the stop pedal.
The trick is, if you have a 88-96 model, you will have to use the factory (ZR1 style - A mod) - or an after market front wheel. If you have a 84-87 you still have to go to a minimum of 17", but can still fit a 91-96 saw blade rim if needed (if nothing more than rolling stock while you build the car).
I had some killer spacers made from VB&P and am slamming 18&19 competition gray C6 wheels on the car.
Forgive the nasty condition of the paint in these pics...heck, there isn't even an engine in it right now: