A friend of mine was able to use his wired Xbox 360 controller as a gamepad. Maybe you could look that up.
I can't really help you, I'm sorry, but I know for sure you can use the same gamepad for all of your emulators. For example, I use my PSP as a gamepad (via the FuSa Gamepad program) for all of my classic Nintendo and PSX emulators.
If I had to pick, I'd say use a wired 360 controller as a gamepad. It's a great one, so why not use it?