Heres some relatively easy to find things that would surely lighten up anyones eyes come xmas day.
BDU's - a different pattern than what he has, sure some are nitpicky about there look but they can always be exchanged.
BBs, make great stocking stuffers, just keep em in the bag.
Gun case, if he doesnt have one
Or simply ask him for a wish list, this works real well for the suprise gifts at any time.
buy sell rating here