It's always a good idea to keep the OEM parts. Imagine buying a 67 Corvette that was highly modified (new engine, seats, wheels) and then they guy says "oh by the way, I have the original seats, OEM knockoffs and the original 427 big block with the three two barrel carb set up". How happy would you be?
The NSX will be in the same league as the Corvette (if not more collectible..less made). Keep the OEM stuff.