While an excellent idea, note that Commodire Pi is at alpha stage, at best. Not quite usable at the moment. You may be better off with an emulator such as vice if you just want C64.
Or get RetroPie which supports:
Amiga (UAE4All)
Apple II (LinApple)
Apple Macintosh (Basilisk II)
Armstrad CPC (CPC4RPi)
Arcade (PiFBA, Mame4All-RPi)
Atari 800
Atari 2600 (RetroArch)
Atari ST/STE/TT/Falcon
C64 (VICE)
CaveStory (NXEngine)
Doom (RetroArch)
Duke Nukem 3D
Final Burn Alpha (RetroArch)
Game Boy Advance (gpSP)
Game Boy Color (RetroArch)
Game Gear (Osmose)
Intellivision (RetroArch)
MAME (RetroArch)
MAME (AdvMAME)
NeoGeo (GnGeo)
NeoGeo (Genesis-GX, RetroArch)
Sega Master System (Osmose)
Sega Megadrive/Genesis (DGEN, Picodrive)
Sega Mega-CD (Picodrive)
Sega 32X (Picodrive)
Nintendo Entertainment System (RetroArch)
N64 (Mupen64Plus-RPi)
PC Engine / Turbo Grafx 16 (RetroArch)
Playstation 1 (RetroArch)
ScummVM
Super Nintendo Entertainment System (RetroArch, PiSNES, SNES-Rpi)
Or get RetroPie which supports: