Have one of these with a drop in throw reflector & convex lens on RS back home for lamping foxes & rabbits etc. will illuminate out to 150-200 yards no bothers.
http://www.dealextreme.com/p/ultrafi...-1-18650-16516
Stock should be plenty bright enough for airsoft, possibly even too bright.
You have to but the charger & 18650 batteries but thats only another $15 max.