Check the on-line rosters of the teams that you mentioned (Oxy, UCSD, CSM, etc). Height and weigh don’t tell the whole story, but it should give you an idea of what’s typical. Of course, focus on the LHPs. You might also find profiles for some of those kids on the Perfect Game site, and that will list their pitching velocity.
Also, use the Perfect Game site to see the recent classes who committed to schools that he is interested in. The “College Commitments” list will link you to player profiles, and their velocities and sizes.
I would also suggest that you check out the club-level baseball at his D1 schools of interest. Many have very competitive teams, and that might be another way for him to enjoy baseball while carrying a demanding academic load.
On a humorous note, if his academics are extremely strong…