I am a first time NSX buyer, I found a 91 with 45k miles that seems like a good price. The car has 17" wheels front/back. Should I be concerned about performance or handling issues with a change in wheel size like that?
I use 17s all around, I personaly think this looks more "balanced" and I save a few bucks on smaller tires. This is the perferd set-up for track, as you want the smallest wheel that can fit over your brakes. By using 17s all around, you have enough room to fit big brakes upfront and keep a smaller rear wheel.
As long as you be careful on selecting tires that are in the range of the original front to rear diameter ratio, there should be no TCS problem.