Ah yes, blinding your friends with your flashlight, good times. You might want to consider Princeton Tec products as well because they will survive being dropped in a stream, trampled on in mud, and quite easy to use.
They have a new light out called the Amp 3 that may work nicely if you would like a light that he could possibly grow into although it may be a little too bright for his age at 40 lumens but it does have a high and low output option and is regulated(will run at consistent brightness for 4 hours before it starts to dim on high from their website but will run for quite a while thereafter). 24$ range
Others to consider would be the:
Attitude-3Led-30Lumens
Impact XL 1 Watt Led 31 lumens
Impact 2 1 led 7 lumens small task light.
All three of these are non regulated but are still more efficent than an incandescent.
You may also want to consider one of their headlamps as well, one being the Fuel which runs at 35 lumens and has three output levels and a flashing feature.
Any of these would work, it all depends on how bright of a light you would like him to carry, personally, I would go for the Amp3 or one of the other newer Amp models from their website. If there is an REI around you, utilizing their "return for any reason" policy is a nice way to give them or any flashlight a test run.
A fellow Scout