I'll use an emulator (gcube) shipped with devkitPPC toolchain, that runs Wii executables too (as I already said, the Wii is a doped GameCube). AFAIK the first gamecubes, named HW2, have a serial port that could be used for debugging. It could be nice to find it for some bucks on ebay

Later, if the compiler grows and if I'll get some spare money, I could decide to buy a Wii