USCAV.com is where I get my gear/BDU's from. If its out of your price range check out something like AirsoftGI.com. Opsgear.com is also a good store to go too. A little pricier than USCAV but its got a huge selection, not necessarily military but allot of 5.11 stuff/Contractor styled gear.
USCAV has a great mix of RS and clone gear, so I wouldn't just go to ASGI.
Opsgear.com, pretty good prices, great selection, more geared tword PMC's in my opinion though.
ASGI has the cheap stuff, but you get what you pay for!
If you want Issued stuff, hit up Ebay. You will not believe the amount of stuff is on there. I would only buy "issued" gear from private seller, there are allot of Ebay companies that falsely advertise "issued" gear. It may say "issued" but its still MilSpec crap!
sticks