Its difficult isnt it. You have a career, you have some children and then life throws you a curve ball and you have a child that you struggle with.
I always find when I have an issue - I write it out in plain English. Then list out a couple of solutions. What I would say from reading this thread is that fees are LIKELY to be a real issue for you. The worst that could happen is you struggle to pay the fees, he loves the school and then you have to pull him out. School fees are blooming expensive and get worse as the years go by.
There was an article in the paper today about some schools being full of pupils from abroad which was changing the culture completely. Fees are becoming so expensive and English is not the first language (although I think for the top private schools they do limit pupils from abroad to 10% or so).
My DS's school had a Parents Evening a short while ago. We were all meant to have 5 mins each with a teacher. The parents in front of me didnt speak English. Our sons werent there so they had a translator and it took ages and then I found myself behind them later on as well so there are sometimes hidden issues with private schools that arent necessarily obvious! Unusual situation but maybe not so unusual in some fee paying schools who perhaps struggle to get their numbers.
So fees are tough and I think you really need comfortable paying them or have a Plan B and Plan C should they become unaffordable.
However, I think - you should be prepared to fight and push and demand as much help as you can from the state system. There is help out there and I agree with another poster, put on the Special Needs Board. Even if you get just a few website links you are off.... Be firm and determined.
Also, having both DS's at private school myself (one in a well known boarding school and another in prep). Some behaviour wont be tolerated, if it starts to affect the other pupils there is likely to be trouble. But what I would say, is that when you are surrounded by boundaries and reasonable disipline it is amazing how you recognise how to behaviour yourself. The norm is to sit down, put your hand up when you want to talk etc. If you see others doing it you end up thinking that is how you should behave too!
Dont believe everything you hear on here from some parents who have never set foot inside of a private school preaching to us all what the schools are like.
Wondering if it would help if you went to an Open Day of a potential school? Schools have them all the time! There is no committment or fees to pay, just have a look around. Perhaps in advance see if they have a Special Needs Dept and speak to the Head of the Unit.
Once you have all the info you can then decide the next step.
All I would say - and please dont take this the wrong way. If you cannot afford the fees at all, dont look at the private system. It will only makes things worse if you end up really liking what it can offer. Of course you might find you dont like it at all but I think you will be surprised just what is possible...