Hi. I'm new to all this as well. Although my DS does not have a diagnosis as this point (we're trying to find a dev. pediatrician) we are trying to find a good preschool. He was in a Montessori program which was an awful fit so now he is in a play-based program. Has only been there for 2 days and I'm not sure if it's a good fit either. On another forum/post someone mentioned Karasik preschool. Here's the link. Could be helpful. I called and had a nice conversation with the program director.
http://thearcofmontgomerycounty.com/program-services/children/karasik-child-care-center.html