HK's a crap place to teach in - take it from me, boyyo - as a rule there are too many little emperors and little empresses in both primary and secondary schools there. By the way, Guangdong and especially nearby Shenzhen city on the mainland are crap places to teach in too.
My advice would be for you to get your chinese L visa in HK for the mainland. Then depart for Guangxi province, and look for work there. In the meantime you can contact Chinese agents, and state your employment preferences. They'll do their best to place you, but you should decline all offers from training centres and private schools. That's because most of them have dishonest headmasters.