First of all, that board is old as fuck. It might be worth $50, certainly not $150. Secondly, yeah, 158 is way too big for him. Since he's 14 and still growing, I'd go for something around 150-152ish. A little big for him right now, but something that should last him a couple of seasons.
"People say that marijuana smoking is going to get in the way of my career. I say to them that on the contrary, my fighting career is getting in the way of my marijuana smoking." -Nick Diaz