Has he attended any kind of a showcase event just for the practice and familiarity with the process? If not it might not be a bad idea to do a cheap local one first. I realize local is a relative term based on where you live. The only issue would be potential nervousness having a first showcase be his dream school. But regardless of what happens I would think size and velocity at his age would get him on a watch list. He should understand at his age it's more about appearances than actual results. He'll be facing far more experienced hitters than he's ever seen.
What kind of throwing shape will he be in when November comes around. Will he have been pitching up until then? Will there be arm fatigue from a long season? You want him in that 82-84 range when they see him. Would it be better to wait to do this next summer?