I only buy Camelbak,Blackhawk and Maxpedition

The suppliers I buy from are either

1.Brigade Quartermaster
2.Ebay ( I have received some good deals, you just have to be careful, look at the selling price and the shipping charges, sometimes the total is higher than buying from a catalog but other times its a lot less expensive)

If your looking for military left overs this place is pretty cheap.

http://stores.ebay.com/A-Z-Army-Navy-Military-Surplus_W0QQcolZ4QQdirZ1QQfsubZQ2d999QQftidZ2QQtZkm