Well on the old boards, there was a guy (can't think of his name) who ran a drag bike based on an auto, and swore by em! They were turboed, and he reckoned the auto trans was plenty strong enough to handle it, and the two speed auto's ratios were ideal for the 1/4 mile.
They were detuned with different heads and smaller carbs (24mm?) and heavier than the manual transmission models, but were excellent tourers with reasonable top end speed, once wound up. For a chopper it'd be ideal for comfy cruising, I'd like to have an original one, just because they weren't popular here in Oz and weren't imported in big numbers.
I'm sure you could fit a K or F head, cam, carbs etc to give it a bit more punch, and not having a clutch lever would give your apehangers that "minimalist" look, particularly if it's gonna be sans front brake too. Go for it! Cheers, Terry.