cyn here
if time is running out for you, just go with the ICCP. Be it St George or YWCA. You can actually do down the schools to pay a visit right? I just feel that the more you think or procrastinate, the more doubts you will have.
For me, when I choose the kindy for my son, I did a round of internet search, then made a trip to the schools and decide immediately thereafter. The school that I selected didn't have much reviews online and even if there are, not very favourable. But I just trust my instinct based on the conversation I had with the Principal. And more imptly, there is vacancy for him and the Principal is willing to accept him.
U mentioned that St George Care and YWCA has small numbers of special need kids, is it better? at least the teachers can concentrate their efforts on your son. I will be concern if there are more special needs kids in the class. What is your plan for him? to go mainstream or special school during P1, that will also help with your decision making.