It needs to be small. It can have a famicom cart slot, but I would rather it be NTSC. Because I am wanting to make a portable on a lowish budget, I can't offer much. Also, I am not interested in retro duo or fc twin. Well, start throwing offers!
EDIT: I am also looking for a GBO. Doesn't matter how good/bad it looks. No dead pixels though.
EDIT again: I just bought a super joy3 on amazon, so I just need the game boy now.