@nomatter: As my impression is that your son’s college preference parameters are so broad as to make it difficult to offer a refined list of schools, it might be wise to enroll him in a summer program at a college or university that interests him. This may help him refine his search even though summer sessions differ in many respects from the regular academic year.
Consider exposing him to an urban campus in a different area of the country. Even narrowing his preferences by urban/suburban/rural & Northeast/Midwest/South/Mid-Atlantic/Texas should help.
Also, several companies offer summer tours of multiple college & university campuses. Probably most efficient in New England or Mid-Atlantic states due to high density of a variety of colleges & universities in close proximity to one another.
Alternatively, since UT-Austin is such a great in state opportunity, consider taking a course or two there over the summer.
Finally, consider attending a sports camp for prospects in his sport in a different area of the country. Gives exposure to many coaches with scholarship money available. Resulted in multiple athletic scholarships for my nephew including to top ten ranked universities (think Duke & Stanford).