I've put together these links to help in the finding of tyres for the NSX for various years.
1991 - 1993
Front 205/50ZR15
Rear 225/50ZR16
1994 - 2001
Front 215/45ZR16
Rear 245/40ZR17
2002 - 2005
Front 215/40ZR17
Rear 255/40ZR17
The tyres that are listed is not going to be an exhaustive list, and even though some tyres are listed may not be available.