maybe i can share some of my experiences here, i am a certified six sigma black belt and i was a six sigma black belt in a motorola's supplier, its hard to say which cerification organisation is good in hongkong. but i am quite happy with my certification organisation which is six sigma institute, i did my black belt certification and completing my professional registration there. you may also consider HKSQ which is working with the ASQ in usa. I was trying to pick up black belt course in motorola university but the cost was too high so i gave up the idea. one thing to note is the demand for Six sigma in hongkong is not very high.
For the project management, i think PMI (project management institute) certification is fine. There are a couple of institutes offering the course for PMI certification and prices ranging from hk$5k to $15k. I be joining the PMI course offer by ABRS in Nov.
if you have interest in Lean, Six sigma institute also offer the course. I complete my lean leader certification there and the course outline is not bad.
by the way, if you decided to take up six sigma you must really work well with statistics and have interest on it because you got tok customise and make use of statistic alot in the six sigma projects.
So far i have complete around 6 six sigma projects, what i learned is practice make perfect, you must do more actual project in order to really pick up,by reading book and pick up some theory is not very helpful.