there is another board on here - the special needs: children board, which may have more traffic than here.
my 6 year old moderate-severe ASD dd goes to an independent special school in Kent (we live in Surrey). her school is an ABA school, and we fought for a couple of years to get her statement naming this school.
does your ds have a statement? usually you cannot access specialist education (whether a unit, or a base, or a SN school) without a statement.
We don't have a statement - we are moving from overseas. The information we have from the LEA is that students do not usually get a specialist placement before a statement, but if the special needs were incompatible with mainstream then it would be possible (and I know this is unlikely due to $$$).
However, I am more looking for info on what level of support statemented or unstatemented ASD primary children are getting in government schools......
My dd aged 6 ASD receives 27 hours 1:1 support from a teaching assistant in a mainstream school. She is statemented and was even before she started school. Frankly the LA will tell you any old crap to put you off. If you think your child is likely to need support then get onto a charity like IPSEA and find out about requesting statutory assessment for your child. Be aware the whole process from requesting assessment to being assessed and getting a statement takes at least 6 months. I also had my dd assessed by an independent ed psych and salt. The quality of support will also depend on the attitude of the headteacher and the class teacher. I looked at several before I decided on one for dd.
I have an autistic child in year 4 ie 9 years old. She has a statement since her diagnosis (well a few months after) when she was 5 years old. She has always needed and received full time 1:1 SeN TA support plus lunchtime break 1:1 supervision. It didn't matter before statement or after the school provided the support - only difference was continuity (4 different TAs as compared to after statement is just 2). It really depends on the individual child's needs. We looked round the special unit for ASD but weren't keen due to travel time. So many factors come in to play. At least you sound like you have a diagnosis - can you say any more about your DCs needs?