For a speed control, you probably need a Zilla z2k (2000a) or equivelent, for bateries you can probably run plain ole' 12v deep cycle batteries, or if u got deep pockets run a crap-load of A123's
Benjamin White
R/c Monster Team Driver
Jq the car, LST, Sportweks turmoil pro
Unconventional Techniques, Superior Results
Let me know what you really need. I have all the info you want about it. Keep in mind, depending on the battery you choose, that could well be your most expensive item on the moped. Are you going to be shooting for a decent speed, but with long range in mind?
Maybe look into electric scooter parts and use lead acid batteries? I used to own a brushless scooter to zip around college back in the day... maybe that would be a good place to start?