From what I hear from Aussie women I know in their thirties, you can forget about it. I don't think the type of guy you would be interested would be in HK and happen to be single. Most come already attached or with the intention of being attached a few times every weekend with a new girl
Not that Sydney is much better for women,what with all the men competing for ..well, men. Any chance you can work somewhere in Europe where you won't get stupid comments like 'oh, you're 37 and still single'...
By the way, there's nothing wrong with wanting to move to a place where you could possibly find someone to settle down with. It's funny how it's acceptable to move countries for work opportunities but not for love opportunities!