AZ Fall Junior Classic would be ideal for your son: attend both the one day academic event and play for a team through the weekend. Ivy's and other top D1's attend thru the wkend. Go to their website and see the coaches who've attended in the past.
I know ONE player who attended the PG Academic event two years in a row and Coach Decker from Harvard was at both. It worked out "WELL" for this player. PG does not let you know which coaches will attend this event. Hit or miss, you'd have to ask that specific school if a coach will attend. It was mentioned by a friend who attended that he didn't see much of any HA D3's there. The HA D3's do attend the AZ Classic though.
With your son being a position player the coaches need to see lots of game actions and how good is the bat. That requires multiple chance to show skills, because sometimes you don't get many balls hit your way. If the BAT is working your son will get attention. Helpful to have a 60yd time below 7.0.
It could be worthwhile to go to either the Oct-Nov Showball or HF camps as a follow up to the AZ Classic. Multiple chances to show his skills within a few weeks of each camp.