"If he's in Scouting, he probably needs a good folder. Fixed blades are officially only "discouraged" by the BSA, but they aren't allowed in many troops or at district activities...A Swiss Army Knife (One Hand Trekker would be great), Opinel, or lightweight lockback like the AG Russell FeatherLite would be perfect hiking knives." - YIKES!
PLEASE - ditch the Swiss Army or Opinel suggestions. Yes, a lockback. I can see no good reason why anyone would want to buy a non-locking folder, but if you must, it's your fingers you risk. Giving one to an inexperienced kid is irresponsible. And since, IMHO, a knife is all about the blade & blade quality, if you're going to spend decent money (over $50) on the thing & then more to have it engraved, purchase something with better quality steel than a Swiss Army or Opinel. It'll be a big deal to him & a teachable moment: show him how to use it safely & care for it properly. Perhaps a reminder, too, of where NOT to carry it (many school boards will turf you out for carrying, no excuses).