If you just need a throttle (no swithches or anything) and looking to go cheap try a dirtbike throttle. I've seen a few bobbers use that set up and it looks nice and clean.
It's only illegal if you get caught.
If at first you don't succeed, use more lighter fluid
95% of Harley Davidsons ever made are still on the road... The other 5% made it home.
New Baltimore, Va '82 CB900c, 1980 CB985F/K 'Mutt"