I would also check out Brecoflex,
http://www.brecoflex.com they offer a FIRST discount of 30% (I think, my memory is a little fuzzy on the number, but they definitely offer a discount). They are typically very fast with orders, especially for stock parts, so if you give them a call, discuss your application with them and ask what they have available for it. I know that they would easily be able to fill your order, even if they do not have a single length to fit they can weld the belts together to get as long as you would need.