how about PLAY cdg?
norikoike makes that kind of t-shirt. but I don't know where to buy in LA...sorry.
there used to be Helmut Lang underwear whose t-shirt is really comfortable, cool, useful and of good quality. (btw, last year at clearance sale here...about $3) and now it's no more.
but there is a rumor that he is to sign a new underwear license.
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.
happiness is the fat girl dancing in the corner