How about a bike shop? (Score 2, Interesting)

Meshing gears are far more expensive than chain & sprockets and require greater precision when installed or they'll wear out quickly. They also need more protection from the elements and do not like at all to be dirty. As for axles, I assume your friend can weld a shaft onto a standard spindle. If you can afford timing belts and toothed sprockets, you can maybe eliminate the need to regularly lubricate the thing - so long as you use sealed bearings. If you insist on gears, try Boston Gear and they'll tell you who your local vendors are.