Adoption
I am afraid I can't help with Vietnam except that a friend of mine did adopt from there and it took approximately 2 years and a lot of money on legal documentation, flights and hotels.
However, for Hong Kong the timing can vary. It will all depend on what your criteria is. If you want a new born baby girl in perfect health with known background it could take forever. If you are less rigid in the criteria, then obviously it can be faster. Girls are in short supply as opposed to boys. We started our adoption process last September and this September we were successfully matched with a 13 month old boy. Some are quicker and some are longer. Sorry about the vagueness, but I don't wish to give anyone false hope that it is a quick process. The Social Welfare Department are superb and the process is painless. They are thorough and ensure that the child gets the right parents as well as the parents getting a wonderful child.
I wish you all the luck in your adoption whichever route you choose. There is one lucky child waiting for you. Give it time and it will happen.