We had/have a great letter carrier in my neighborhood. He was stationed on an aircraft carrier. We did the typical holiday bonus in an envelope, sometimes we'd meet him at the top of our driveway and talk for a little awhile.
Somehow he was kept informed of the whole process while I was applying to academies.
When the CGA appointment came, he hand delivered it to the front door, braving multiple very friendly dogs to ring the doorbell and hand over the appointment.
Good luck with the decision process, remember it isn't always about the school, but the branch and service required after. Go with where he wants to see himself in five years, not in one.
Again, good luck!