We (SG-21) are actually part of SG Operations.
Stargate Operations: The Home Base of SGC & SG-SOCOM
I know the costuming is not screen accurate and it doesn't bother me, it's actually kind of intentional. Never one to follow rules I decided when we started SG-21 that we could use updated gear and that our team would exist "after the shows ended".
Our website
Louisiana Star-Gaters: SG-21 has a PDF that details the gear we use. Basically it's all made by a company called Rothco, with the exception of the boots which are Bates Enforcers.