I definitely like the idea of starting him of in the over-8 rep range. From there, the thing to remember is no muscle failure ever, never, ever, ever, never. That's one of the leading factors which can contribute to the "weights stunt your growth" semi-myth. No failure means no problems.
With that in mind, my instinct is to go either with Dan John One lift a day, for it's insane simplicity, or a bastardized version of Waterbury's next Big 3 (bastardized in the sense that, instead of 3-5x3-5, I'd start at 3x8 on the moves, and drop a rep or 2 each week, until you get to 3-5).
No matter what you go with, the rules are:
- No muscular failure.
- Compound exercises are like water, more is always better.
- Recovery is key; you may need to reel in his enthusiasm.
- Technique above all else. If he wants to cheat a movement, he doesn't get to play with the iron.
- Full range of motion, at all times. Squats are deeeeeep. Pull-ups are dead-hang. And push-ups are nose to the floor (yes, he should do push-ups).
Let us know how he progresses.