Toss in a couple of Photon II's or Freedoms in red, green, blue, and white. Those are good for seeing, night vision, and signaling. Plus some spare batteries for each. Cheap, low tech, and ready to go. The Freedoms clip with the magnets is a nice touch and useful. Cheap & easy is the way to go when the crap hits the fan.
Geez, I still get awful skeezy thinking about sending 17 year olds out to where they can get shot at. Too damned young! Oughta wait 'til the stuff behind their ears is dry at least. If we gotta send kids that young to war, this sure can be a crappy planet somedays.
Buy the kid some, nope, the heck with that, not some -- a whole pantload of kevlar, and make sure he knows how to duck real darned good, for crying out loud. And if he says he'll be real brave, smack him in the head good and hard! I hate seeing children be brave. Scares the crap out of me every time. Be sure he listens to the old guys, it might save his butt.
Good luck & Godspeed!