you can only get a HK ATPL is u are going to work for a company in HK. Your best bet is to the Ozzie one as its well recognised, u can then get your kiwi one based on your Ozzie one(trans tasman agreement). If you plan on flying around the world , the FAA ATP is handy one to have, and only takes a few days to study for the exam, and a flight test in a light twin.Hope that helps.
Cheers FM