While your son is only 2, you should be planning ahead as in 2 years they will be starting reception or kindergarten at most international schools (and as weird as this sounds, that means you need to start applying NOW for some of those schools--yes, now). I mention this not only to warn you of the need for applications but also as something to consider in your house hunting. If you have your heart set on a specific school you'll want to make your housing choices relative to the commute your partner and your child will have to make.
I know it is a bit early, but it's not something to ignore.
My advice on where to live would not be focused on proximity to nature as most things in Hong Kong, from paths to parks to beaches are not that far away by taxi, but on what your building offers in the way of entertainment for a child. An older walkup for example won't have a playroom, pool, or outdoor playground, but some of the newer, larger buildings will have dedicated areas for children to play, mingle, mix and have fun. Our building has a 3,000sq foot playroom with a padded jungle gym, slides, nets, etc which is a haven for families in the building. Having that place for them to go, outside of the house, is basically a "relief valve" for them and for us as we have times in our place that are quiet and peaceful while the kids are having a "kid life" playing with friends. As you look at different places, don't underestimate the value of something like this, even if it is in a more urban environment.