Combat sports is a good site. I make it a point to only buy from sites that sponsor fighters. Not sure if CS sponsors guys. (I know they sometimes offer fighters a discount)
You might also want to try
http://www.primetimefighter.com/ these guys make it a point not to sponsor fighters. But!!! They have been known to give equipment out to guys that need it and can't afford it. They do things because they feel it is right. They usually don't want the guys to know were the stuff come from. That's kewl!! When you see someone with their stuff they want you to know it is because the guy likes it, not because he was paid.