We did get him the camo vision sun glasses - when wife saw them, she said "we have to get those"... and we got a pair for his friend.
Thanks for all the ideas. The lifetime license would be awesome, but out of our price range right now. Also, I've bought his last two hunting licenses, I kinda want him to buy his first "adult" license.
We also got him a 3 piece military ECWS sleeping bag from Sportsmans Guide:
Son and I were just at a friend's Vermont cabin this past weekend, and the nights were in the twenties, son had to borrow a warm LLBean sleeping bag. So we got him the above bag. I've had very good luck with Sportsmans Guide, I hope it extends to this sleeping bag.