Tony: the truth is you need to decide what your priorities really are: your wife, son, career, desire to live overseas, etc... And you need to make your decision according to those priorities.
You also need to assess whether her decision not to come to Hong Kong is a logical, thought-out decision on her part, or if she is just simply afraid. If it's the latter, then certainly some persuasion, coaxing and comprimises would be in order. If not, then you need to choose which is more important to you. Either way, don't try and do a long-distance marriage with you in Hong Kong and her not, that's no marriage at all in my book.
Rebekah: not all marriages break up after moving here. My wife and I moved here from the states and although, it hasn't always been an easy transition, it has strengthened our relationship. And, while we may not want to stay here long-term, we don't regret our decision for one second.