Is it his first PCP or his first air rifle ?
If its his first air rifle of any type I'd go for a springer as a self contained unit, & also cheaper if he decides it's not for him.
If he already shoots a bit & it's his first PCP the AA400/410 would be my start point with plenty of good used outfits on dealers racks, a pump is a good idea because having to refill will slow down his shooting speed & teach him that it takes a bit of effort before he can enjoy the benefits.