Yess, that's cool. If you like to use the NES, SNES and Genesis emulators, you'll need the CCPro. This emulators are really good (the GBA emulator is good, too).

I got a black Western Digital Passort 500 GB (50 Euros), but that's almost too small for me now. I'd buy 1 TB now, but that's not really important. You can always buy a larger HDD in a year. Or two.

You can watch all your AVI movies with your modded Wii from HDD, too. This alone would be worth the cash, imho.