Recommend me which Early Intervention should I go?

Which Child Development hosp or centre can any1 recommend ? My son was heavily recommended from his childcare school for EI. I request a memo from his school. I believe he may display different behaviour at home & school. The memo written only 50% accurate. He is 3yrs old this yr, most children at his class were smart. Able to read from storybooks. Sometimes I feel that the school trying to push him out of that Centre. Set aside. I choose to visit poly and waiting for referral. I hope I'm choosing the right diagnosis centre for him. What happen if he is diagnosed w Austism/Adhd? Can he go onto normal pri/sec school in the near future? Or must he attain a special school from now on meaning will his current school kick him off from the current centre if his diagnose is confirm? He can no longer go into a normal childcare centre?