A lot of it is about fit as well. A Stanford Engineering professor for grad school told me that one of the most important things for admissions is Rec letters, not necessarily the prestige of the undergrad.
Prestigious undergrad will get you rec letters with more weight, but it is ultimately up to the student to be active and do research with a professor at the school.
Is he able to visit any of the schools mentioned? Does your son have a preference to which school he likes most?