Are you on HK or Kowloon side?
I am more into Muay Thai and train at a gym in Prince Edward.
Gym is small but you get to train with Thai teachers.
Not a fanatic at all, more like trying to lose some tires around the waist.
If your on the HK side, i believe gym Impakt does MMA.
Trainer is Alain Ngalani who also fought Bob Sapp recently
http://www.youtube.com/watch?v=NtIUrPObzZY
Not a 'fight' at all