Hi metalmeltr, You're in pretty good company here, as a couple of the members are also metal workers. I don't know of alot of sources for motors, but I do know that people who experiment with electric vehicles make use of used electric forklift motors. You might find some sources on the web for these. I'vr ran across them from time to time, but I don't have the links. Anyway, good luck!
PS: Also, look up e-tek motors. They are small, light and powerful. They are also expensive, but you can sometimes find used ones on e-bay.