If I were you, I would look into using the fight pad. It reports itself to the Wii as a classic controller pro and so should be compatible with all games that work with the classic controller pro, but it is shaped like a GameCube controller.

I've never used one because I have a white Wii that accepts actual GameCube controllers. However, this is what I would look into if I were in your situation. It is an officially licensed product, so it should be of pretty good quality I would think.