go and have a look at the school he is due to start at, and at any others in the area.......get a feel of the school, (without the tour bit that you should no doubt have already done for the yr6 secondary tours).
talk to the teachers, maybe even some of the older kids (maybe the yr10's, or even if poss any yr11's you see, as they won;t be there when he starts and might speak a little more freely about a school they are leaving)..........see how they find 'flambouyant boys' fit it.
I have two aquaitences(sp?) (I know them but not closely enough to say they are friends IYGWIM) who have sons who are definately what you would call 'girly'......love dance, acting, just not your typical boys in any way......altho they are actually fantastic lads (my girls are friends with them).
anyway....they both went to different secodary schools, both single sex schools, both marked as 'sports academy's', both were unhappy. They weren;t bullied, but they were not accepted fully as they just didn;t seem to gell with the 'jocks' (american term I know, but as I am not in the mind-frame of teen boys, I only know high school musical term......I have teen girls, thats MY excuse).
anyway...........they are now at a new school, the same one in fact. It is a mixed secondary school, focus strongly on performing arts, in general more fitted to these boys, and they LOVE it. they have made lots of girl friends, are very popular with the boys at the school for that fact, and simply in a school now more set to their needs and interests.
I am amazed that something so simple as a different type of school has made as much as a difference as it has to them. they 'strut' now, they are confident lads, they are 'cool', as opposed to being slightly different, and you know, I think their mums are fantastic for accepting their boys as they are and not pushing them to fit somewhere that is worng for them. Thye will both go out into the world happy confident lads now as their secondary schools are not damaging then, and I bet many of us can remember what it was like at secondary school, and how nasty some people can be (I remember).
you know him best, and you love him for that, so he already has a good grounding....now you do what you have done already, and continue to find the best place for him
FWIW, I have the same with my DS2......he is a very flambouyant child, loves singing and dancing to mama mia and HSM, and has blonde curls that he is growing back as he likes longer hair. he is nearly 7 at the moment, so things could change, but if not, he will be going to the school the lads I know are at, altho his brother (DS1) will be at the sports academy as he is definately a 'jock',
good luck, and don;t fret......he will find his niche, and he will be cool with it I am sure.......his mum is behind him, which is 90% of the work done!