I did a NES case’d setup. I modded the plugs in the NES to simply pass through the 4 usb wires. then made a little Female USB to male NES dongle. for my SNES controllers to USB i use something that looks just like that. NO reason that wouldn’t work. But I’ve spent the day working on a gift for a friend’s husband, and she bought one of these http://www.amazon.com/SNES-Controller-Adapter-USB-Super-NES/dp/B002IXZ5DE/ref=sr_1_1?ie=UTF8&qid=1418536917&sr=8-1&keywords=usb+snes+adapter

2 adapters in 2 cable? good deal in my book.

the power button turns on and off the PI, and I want to wire up the reset button to the Reset Emulator button. I could do the GPIO, but after having done a RetroPie Mame cabinet and just doing a $3 keyboard hack…I think I’ll do that. I need 1 button to do 1 thing, and a keyboard hack is REALLY cheap and REALLY easy..and I’ve got a free usb port inside…so….should be real easy.

Haven’t done a GPIO adapter….but like I said..if you’re putting it in a big enough case (the keyboard encoder isn’t big, but it won’t fit in a standard raspberry pi case) …keyboard hack is the way to go..IMHO