Hi Sally,
I am from Eastern Sydney myself. I currently live on the South side of the HK Island.
My suggestion would be similar to Tung Chung Mum?s reply, which is to live in a serviced apartment first and decide where you would prefer to live before making your final decision. Depending on what you like compared to Sydney ? like convenience, crowd, open space, park etc, you might want to take those into consideration.
Since you are sending your child to AISHK ? it?s quite central in terms of location in HK, either drive / busing/ MTR (subway) to this school seems quite easy.
For owning a car, the cost of keeping a car compared to Sydney is about $HK3000 - $3500 a MONTH here for a car no more than 2.0 litre capacity. It may not appear expensive now that AUD is high. It can cost less if parking is part of the accommodation cost from husbands Expat package.
Personally, I would not live too far out like ?Clear Water Bay? or ?Gold Coast? Area - travel can be inconvenient. South side or the ?brand new building? - ?Bel Air? ? it?s part of Pokfulam area, is where I personally would like to live, because it has more open space and for children to run around, facing the South Sea, less polluted, not as crowded and much quieter. Easily accessible from central HK district by car or taxis. (You will find Taxis are quite affordable here in HK compared to Syd). For AISHK, there might be a school bus which can cater the pick up and drop off to your home, check with them. Bel Air / South side does have a lot of Expats, you will want to live around those area because of shopping conveniences, parks and beaches.
Word of warning, the Summer here is really horrible!
Anyway, I hope this helps you somewhat?.if you want, you can email me directly.
All the best.
S