A laptop should be purchased based on the software to be run on it. Most software applications have some minimal, recommended, and "best" hardware recommendations.
What classes will your son be taking? How will the laptop be used accordingly? Check with the Uni and/or the Department in which he intends to major. The Uni or Department may already have some recommended software and hardware (laptop) lists.
And maybe even some discounts if you purchase via the Uni.
Be sure to get some extra insurance on whatever laptop you purchase in order to cover repairs and theft. Uni is hard on laptops.....
Do read the policy carefully - often lots of fine print that actually limits what is covered.