We get ours at Walmart. They carry a ton of packs of Gildan, fruit of the loom, Hanes etc. We have a large program and have never had an issue of them not having enough. If I ran into that situation I would go to the Walmart an interstate exit up. City/suburb perks I guess that I could easily hit 6 different Walmarts in 30 minutes or so. Every girl is given 1 pair with their camp clothes, any extras pairs are up to them to buy. As long as they are white crews, I don't get technical on brands. You cannot tell the difference when they're all wearing them anyways.
This year we got printed crews as well. I have no clue what brand. A local printing company did them.