First of all, I am guessing you didn't buy the car new in '92, so you don't know when the tires were actually bought? In which case, check to see how old the tires are, and examine them to see if there is any cracking. To see how old the tires are, follow these instructions:
Determining the Age of a Tire
The Tire Rack says that the practical life of a tire is six to ten years from the date of manufacture, as noted here:
Tire Aging – Part #1
Tire Aging – Part #2
If the tires are more than ten years old and/or show significant cracking, replace them.
I don't see any need to replace your original 15"/16" wheels. If you want to do so for reasons of aesthetics, by all means do so, but otherwise, you can keep using them, with tires in the original sizes of 205/50-15 front and 225/50-16 rear.
As noted above, there are lots of choices for the stickiest "extreme performance" tires in those sizes, but since you're less concerned about performance and more concerned about ride comfort, you might be better off with some "ultra high performance summer tires". In that case, I recommend the Yokohama S.drive. Same thing if you decide to get an extra set of wheels from a '91-93 NSX, which are quite plentiful, although they can be more difficult to find if you insist on pristine condition.
If you decide to get OEM wheels from a later year NSX, I recommend the '94-01 wheels, which won't need spacers like the '02-05 do. Those wheels are 16"/17". Again, there are several "extreme performance" tires available, but since you're less concerned about performance and more concerned about ride comfort, I recommend an "ultra high performance summer tire", specifically the Bridgestone Potenza RE760 Sport in 205/45-16 and 245/40-17.