Discuss the wholesale blanks industry: Factory direct, custom labels. You can also use this forum to locate a wide variety of wholesale products including t-shirts, hoodies, mousepads, coffee mugs and other imprintable products.
If you see something on that site you like, your best bet would be to contact the manufacturer of that jersey and see if they will let you set up a wholesale account.
They make motocross jerseys for many factory riders and teams. My stepdad bought a Redbull Answer Jersey from them through ebay and it looks exactly like Josh Hansens jersey. It is really nice and even has the sun and bull logo on the end of the sleeves by the cuffs like all the Redbull sponsored riders. They also make the Pit Shirts for team Factory Kawasaki and apparel for other sports such as bicycling. I hope you ride KTM. Are you going to Anaheim 1?