We discovered a number of options for high stat kids like your son. Do you know how important it is to him to go to a private school, or a small school? There will be a lot of suggestions based on kids who got great merit aid for particular schools and programs. In our case- DS20 had good outcomes applying to a few schools known for guaranteed merit aid. What we discovered is that even though they are large public universities, they each had great ‘specialty’ programs that could help him create a much more personalized experience. With your sons stats, he would qualify for full (or close to full) tuition, leaving you with about 12-20k per year for living expenses/ books/ travel etc. A couple of well known examples are University of Alabama, University of Arizona, University of New Mexico.
Also- and idea how he did on his PSAT? If he is a potential NMF or NMS, some schools have some really fantastic merit opportunities.