Talk to the guys with Combat Challenge. Start there and see what you can come up with, I know the Arizona Army National Guard is always trying to lend a hand.
The nice thing about AZ games is they aren't oversized, over the top, and out of control. Logistically speaking I have no clue how you'd fit 500 people playing airsoft anywere outside of Camp Navajo.
And please don't even try to push organized mumbojumbo on us, we're a red state and don't take kindly to socilized airsoft :mrgreen: