American apparel ROCKS!  make sure you get a tax ID# to order from their site, they are relatively inexpensive, but at wholesale they cost like 4 bucks.  They're located in LA so you might be able to buy at the wharehouse.  I would recommend using a local screen printer, that way you can oversee everything.  Also, a lot of printers use American Apparel and include it in their cost.  I would ask around.