I don't believe I've seen such an animal - a shorty generator. I think someone above mentioned a black powdercoat alternator - and use a one wire / self-regulating version with a single #6 welding cable back to the starter solenoid. Cover the copper attachement lug with a shrink-wrap sleeve and generally make it as black as possible. You may have to paint or powdercoat the pulley and cooling fan to get them to "disappear' too.
You won't regret having modern electrical power on board.