well i've rethought this....at least for now....
i just purchased 2 NES usb controllers. not the adapter thing, but two new NES pads with usb ends. i have an old laptop that still works and i think what im going to do is put NES emu and roms on it and just plug up my controllers to that and test with that for a while and see how i like it. if i end up wanting to play SNES games in the long run, i'll probably end up opting for a larger hard drive so i can put snes roms on it as well. and the other good thing is that by keeping the pads usb, i can always hook them up to my mame cab and play making it a little more universal.