I didn't look at any of the specifications, but REI-brand sleeping bags were always a good choice for scouts: rugged, durable, and lower cost. (Of course, that comes with a weight penalty - but they're young and strong; just keep them from dragging too much other junk - like clean underwear - along, and they will still carry a fairly light load.

I don't know how tall he is, or how he is built, but REI offers 3 youth bags, if the adult regular bags are too large. Unless he'll only be camping in mild weather, don't buy a bag that is too large "so he'll grow into it." If it's too oversized, there will be too much dead air for him to heat up, and he'll sleep cold as a result. (If you do go that route anyhow, he can fill up some of the space with extra clothes - but that's just additional pack weight and damned inconvenient.) Buy him a bag that fits now, and then replace it in a couple years if he outgrows it. If there's a younger sibling, the bag can be passed down; if not, he can always sell/give it to another newer scout when he outgrows it.