@PeterH, sorry forgot to mention sealed lead acid batteries. I have access to welding and metal working equipment so i was intending on modifying the frame so they would fit and be protected.
@GoForSmoke, i have considered using an ac synchronous motor, they have benefits in efficiency and speed, i think. But getting all the electronics equipment to do this is very complicated. DC-AC converter, variable frequency drive, blah too complicated. I was also thinking of regenerative braking, you read my mind.
@MarkT, thats a little saddening but hey i think you learn so much more whn you try things yourself.
So for people who want specifics i think 4 75-100 amp hour sealed lead acid batteries. 48 volts seems a little more reasonable to me. motor could be a briggs and stratton etek pancake brushed 48v 150A continuous. Thoughts?