I'd guess more kids throw slower than 82-84, and more are below 6'. Does your son sit 82-84, or top FB 84 and he sits 80-82?
Has your son ever been critiqued at a PBR or PG or some other showcase? What did they comment about your son? I'd find an inexpensive local camp - showcase to get some feedback specific to your son's skill level. (Plenty of kids throw 82-84 and are all over the place, don't start on their HS Varsity teams). Does he pitch for a reputable club team? What does that club coach say about your son? You need third party reputable observations so that your son gets a reality check and you can best guide your son before you start traveling all over the country.