I will have to add it to my "To go List" for the next time (there was a url link here which no longer exists)I am around HK along with bringing a bigger suitcase!!
Not sure if I can post website links but I found this one helpful for me. There's 3 parts with some good information
http://www.japancamerahunter.com/2012/06/hong-kong-camera-hunter-pt-1-film-in-hk/
Be careful though, you're treading a steep path with all those cameras available to you. The mamiya is a more than capable camera and I'd recommend getting familiar with that before having your head turned by other cameras.