Ah, I think I know what might be confusing you. If you've seen places on ebay saying "this RGB cable will work on anything but the SNES" you can disregard it, they will work on anything but the PAL SNES.|
With that in mind I think this will work just fine for your NTSC system:
21 consoles, 5 handhelds, 2 PCs, 1 Mac and about 700 games from the past 30 years. Every major manufacturer and developer represented. Still a fanboy for disagreeing with you.