finding the right school in North Yorkshire, look for some help!

I am currently in the middle of moving to North Yorkshire from East Sussex and wanted some advice on independent schools around the area. My son is 12, He really needs a specialist school with small classes. He does have an EHCP I was wondering if anyone knew of any schools that might be able to help me. He is currently home educated as he cant cope with mainstream schools( noise, large classes, 1:1 etc)  everyone we asked said they can't meet his needs. 

I was also wondering how easy it is to get into a specialist school in North Yorkshire as here in East Sussex its very difficult and we are in the process of trying to change his EHCP as our LA says Mainstream school can meet his needs even though they have been told Mainstream cant meet his needs, one even said he needs a specialist school. 

Any help and advice would be much appreciated. Thank you