ATPMBA
I am in HK at the moment, and the only AOC helicopter flying is HeliServices based out of Kadoorie Farm near Shek Kong. Kai Tak is used by the HK Aviation Club, however it isnt a licenced heliport due to its location and approach/ departure downwind. Chep Lap Kok is used by the Gooverment Flying Service, and isnt open for GA traffic. The only other runway, and Shek Kong is a PLA military base, open on weekends only.
It is for these reasons, that the number of aoc operators is limited.
Hope it helps and dont hesitate to ask!
Oh and I forgot Sky Shuttle, operating AW139's out of the macau terminals in central , its an elivated heli deck (so twins only) and suffers from some noise abaitment.
s