If you look in Southern NY you should be able to find many good school districts. As far as the special needs aspect, most districts I am familiar with in Orange county NY are excellent when dealing with autistic disorders.
Check out this link:
http://209.200.89.252/search_site/ it is the autism society of america. You might be able to join a local support group or even find a good physician who can share experiences about the local schools.
I am a pedi RN my prior job was at a children's hospital dealing with many different disorders. One thing I have found is a good support group can really help parents go from treading water and feeling fearful and hopeless to empowering them to help their their family live their lives to the fullest and understanding how to advocate for your child. Good luck with the lil guy!