This is my first post on styleforum, and I make it because I suspect you are in the same position I was about six months ago. I was scheduled to go to HK for other reasons, and I decided to have some suits made while I was there. Although I knew that HK was good value in terms of the price:quality ratio, I didn't have the necessary knowledge of fabrics, tailors, silhouettes or fit to direct the process with any confidence.
Although I first had bespoke suits made in 2007, I was lucky enough to stumble upon a good tailor and had a good experience without really understanding the details. This time around I decided to research the topic of classic menswear. I found there are many valuable online resources including, to name a few, Permanent Style, A Suitable Wardrobe, Die Workwear and London Lounge (for the more advanced and staid). I found styleforum to be the most valuable of these for its combination of historical grounding, range, expert commentary and interactivity. Thanks largely to these sites, I went into the process reasonably well informed, I had three suits made by three different HK tailors, and I was happy with all three results.
You should be aware that a question in the terms you have posted would generally either be ignored or be met with the suggestion that you should search the previous posts in which the matter of tailoring in HK has received extensive treatment. This is fair enough, as a lot of knowledgeable people have expended a significant amount of time and effort to record their experiences, and it is simply too tiresome to repeat that in response to every new and uninformed question on the same topic. But, as I said at the outset, I have some empathy/sympathy for your position.
Should you choose to browse, you may wish to take particular note of the following posters, amongst others.
The educators/purists/intellectuals (and in my experience the most instructive, whatever your taste or philosophy might be): Manton, mafoofan.
The exemplars: voxsartoria, iammatt, whnay, maomao, Baron.
The iconoclasts: Doc Holliday, edmorel, dopey, Label King, gdl, Victor, oldog, Moo, Goomba, nildawg, Eustace, Phat Guido, New York Ranger/Islander (is this the same person?).
The more "exotic": NORE, NOBD, Spoo, etc.
The best posts I have read on this particular topic (ie going to a tailor in HK rather than the HK tailor going to you), are by slewfoot circa 2010. There is also an excellent series of 3 comparison articles by Jonathan Lai on A Suitable Wardrobe.
As you have mentioned full canvassing and hand stitching, I presume you are looking at the mid to high end of the HK tailoring spectrum, and suits rather than shirts. At the risk of gross oversimplification:-
Best HK high end approx US$1200-2200 (depending on house and fabric): WW Chan, A-Man Hing Cheong, Gordon Yao, Y William Yu.
Best HK midrange approx US$600-700 (and my choice at this price point): Peter Lee of Lee Baron. Maybe Roger Concept.