As a teacher do you think you will work in Primary/Secondary school? Private? University? Language schools? There are many options but each will greatly influence where you may end up working. How much travel time are you and your husband each prepared to tolerate so you can live in the greenery and nature you want? Hong Kong is primarily an URBAN CITY. True HK does have islands, and country parks and green places, but sometimes living there has drawbacks....e.g. living with other expats trying to get away from the city, cost etc.
One of my associates moved to the sheltered "Green place" for better air quality, but says that in the last 5 years things have deteriorated and the air is no longer as good as it was.