i was in this boat too about 3 years ago. I'm from austin and had a 92 avg at a private college prep school, my sat was 1410. I major in advertising here at UTexas. My advice: find the best school that also meets your social needs. I could have also played D3 lacrosse, but i didn't like small schools.
So:
research yourself
visit one small one medium and one large school
which one does your son like the best?
now, find the best business schools that are that size...and proceed accordingly.
as for college lacrosse check
www.uslia.com -the club teams are pretty competetive (d3 level at least for the top 25-30 teams)