OUR UNOFFICIAL ANSWER
Thanks for your message.
I would say your best bet is the Trade Development Council (a government
body whose job is to promote trade with Hong Kong) and the Film Services
Office (another government thing whose aim is to promote HK film industry).
Here are their websites:
http://www.tdctrade.com/ or http://www.hkfilmart.com/default.asp?
Btw, actually the HK film industry has been struggling in recent years
perhaps due to all the pirated VCDs.
Most of the younger generation in HK (50 and below) have studied English. So
you will have no problem especially if you will be dealing with ppl in the
film industry. Just don't talk too fast! As for the percentage of bilingual
ppl in HK, it is hard to say since it is all relative.
Have a great trip!
p.s. If your real name is Steven Spielberg, I want a part in your movie!