ah, if only getting a statement was a matter of choice.
I know of children with a diagnosis of asd who are not statemented, partly because the parents were laxadaisical and some of them because they believed their school that said "they" would do it for them.
Nat1H hits the nail on the head. the language you use in making your parental application is uppermost important.
You are going to have to convince that your child needs more help than a child who does not have a "disability" and that in order for your child to access the curriculum, help is needed. this will include speech therapy (good luck) OT (even more good luck) and of course a full time aide if you think he needs one.
LIst your child's difficulties in as much deetail as possible in your application bearing in mind that all you say must tie in with what they want to hear.
basically, the long and short of it is, your child will receive when the LEA deems that he is going to be a "nuisance" to a regular and often untrained teacher in ASD.
If your child is going to a special school, you might not get much in your statement over and above what is being offered by the so called specialists in these facilities.
special schools think they have all bases covered and that they can provide what your child needs.
in my experience this has not been so. for example you wont generally get a 1:1 aide in a special school because the classrooms are already geared for a low teacher/pupil ratio.
its a minefield but you can do it, and the sooner the better