You also may want to take a look at Stock Drive Products:
http://sdp-si.com/eStore/CoverPg/Drive_Components.htm
They have a large variety of belts and pulleys, and they ship reasonably fast as long as they are in stock. Their selection is so large that they actually have belts and pulleys which aren't offered directly off the Gates website. If you are looking to drive these pulleys directly off of a wheel I'd recommend Gated GT2 or HTD tooth profile with at least a 5mm pitch.