I've never posted here before, but your situation really touched me. Have you actually been offered a place at the independent school of your choice? If so, would the head of the school be willing to help you with appeal? With all the professional reports on your side, it is difficult to see why the tribunal came to their decision. Have you approached the NAS?
They may be able to help.
Most professionals agree that an EBD school is not the right environment for ASD children. It was disastrous for my son, who eventually went to an AS specific residential school.
It sounds as if you need to appeal his statement as well, if speech and language needs and OT needs have been ignored.
I know the energy required in fighting all this, but please don't just take it lying down.
I wish you well, whatever you decide to do, but you need to act quickly.