Thank You for the sugestions...
My biggest issue with the extension cables are that they have no way of mounting in the cables, although it is possable to build a bracket. I am assuming for nintendo that it would be easier to use the four score, or to just assume only two players. I am assuming you can not plug into the "new port" with a four score due to USB issues - therefore it would be limited to only controllers, and possable quick shot and advantage.
I found a dead SNES locally for 12 dollars, a nintendo can be had for a few more, same with the genesis.
The other solution is to just convert the controllers to usb, but then I want to use them also on my real NES...