Not quite on your original topic, but my own experience of intelligent and gifted children is that if they get into the mindset that they are different from other children at an early age they tend not to socialise with them, and never learn full social skills as they grow up, which are extremely important for adulthood. I think people (particularly on LW sadly) underestimate the importance of generalised social skills, and how much can be learned from interacting with people who are less 'intelligent'*

While meeting other 'gifted' kids with similar life experiences would definitely be good as you've said, it would also be good to see if you can arrange for him to have activities with other kids his age. One possibility might be to find activities where he's not operating at a much higher level than them (maybe sport/arts/music?) so he can interact without that being a barrier. Remember however clever he is, developmentally and psychologically he's still 14 and has a lot more in common with people his age than adults.

*(Scare quotes as there are a lot of issues with defining general intelligence, and it doesn't necessarily correlate that well with academic success at that age.)