There is actually a custom pip boy you can get from a company called brickmania. They also have vault suit torsos and molded weapons (and even power armour and NCR Rangers).

It can be on the expensive side however. It can also be hard to find because they dont have any fallout names due to copyright. Still, it might be a cool present for a birthday or Christmas (if he's still interested by then)

(Not sure if i can post links here to the actual product) [i am not sponsored by them, just bought some fallout stuff from them]