You can check out geoschools (
http://hongkong.geoschools.com/) which has a lot of HK specific info. Parents are fairly active on the forums so your hk based questions will be answered quickly. Just be sure to ask some more specific questions and you'll get very detailed responses.
It can be tough finding spots, but the pressure is less for kids in your age range. Consider things like is the company footing the school bill? will they have debentures? where in hk do you want to live?
HK is a great city for kids that age, very safe, very easy transport system... pollution is a mess, but women in hk live longer than anywhere else in the world on avg, so maybe its not as bad as it seems...
Best of luck.