I've recently become aware of how much I love my wireless xbox 360 and ps3 controllers and I kinda want to build ones for other systems. Namely the NES, SNES or Genesis and then based on that success or failure continue on to some other systems. The only things I really want are that it is completely wireless (i.e. don't want to use the NES Satellite peripheral) and that it be rechargeable.

I've found a few guides for building wireless controllers out of NES, SNES and Genesis controllers for use with the Gamecube/Wii, but I actually want to use them on the original systems.

Can anyone point me in the right direction to get started?