I'm a nitro man through and through. But I'd have to say if you're not mechanically minded or have a lot of patience, they're not a good choice for a beginner.
The engines are dead simple, a carburettor that consists of a slide and 2 needles that regulate fuel, a 2 stroke design with a tapered bore and a glow plug that ignites the fuel. But they can be temperamental, running them in is a ball ache and very boring, and the variables with environmental factors can leave the beginner stumped as to why their car isn't running right or not atall, do your research, have the patience and learn about the engines, all the knock on effects of carb adjustments and you're quids in, and they're a hell of a lot of fun, but for a kid of yours' age, they'd get fed up in no time, I would.
Stick with electric for now, the only thing your lad will get bored with is waiting for the batteries to charge!
As for cars, I don't have much experience with electric, I built my first, a Tamiya Land Freeder cc01 just the other day, but I can recommend FTX, as I have the nitro Hooligan, and as the plastics aren't the best quality, I've found they're pretty well put together, won't break the bank and the spares are as cheap as chips, if he breaks something he'll most likely be able to replace it with his pocket money I think your lad would enjoy an electric Hooligan, I've ran my nitro one through reasonably long grass and its coped well, and the protection the big foam bumper at the front gives is good.