I do have some advice and experiences to share with you on the application in general, on how to be more effective and draw attention and response. It also depends on what you really want to achieve.
If all you want is acceptance into a PhD program of the area of your choice, it should be fairly easy and straightforward for your background. Except for a few very hot areas, in general, PhD programs in Canada are not difficult to get in. As long as you satisfy their requirements, the chances are very good, even if you just follow the normal procedure of application, with no special effort to communicate with individual professors. All you need is to follow the procedure instructions they specify and meet the deadlines for all the documents they need.
But if you want partial or full financial support to be part of your results, then you should take a more informed and planned strategy to approach professors. Keep in mind that if an area is not hot in market, almost all PhD students get some financial support in some form (Teaching Assistantship or Sessional Instructors from the department, Research Assistantship from professors, Fellowship from the school,etc). That is the way they attract and keep people to stay in the programs for years to finish the degree, for otherwise people who cannot support themselves will just stop half way and go out to work for living. But the difference lies usually in whether you get a financial support upfront versus whether you get it after you enter a program. Hot areas may be exceptions as too many people want to get into the program and there is not sufficient financial support to help all. But in North America, as far as I know, most PhD programs are supporting their students but master programs are much more difficult to get financial support. A hot area like computer engineering for a master degree rarely gives support to the students who usually get support only in the summer when they find work for some companies as interns or something.
I do not know how hot your area is and whether most students in the PhD program do get support. But the general situation is, the more difficult it is to find an industry/society job for that area in the market (not counting the very few academic jobs such as professor jobs or research jobs in big labs because every area has a small percentage of PhDs lucky enough to get academic jobs), the easier you can expect financial support from the department. This is understandable because otherwise the system cannot sustain itself. That is the reason why you see the North American universities keep producing PhDs in many areas, who are out of jobs as soon as they get PhD and for this reason who try to delay the graduation as late as possible. Not few middle-aged students are stuck in the “black-hole” of PhD or in several rounds of post-docs without the hope of getting a real job and losing abilities of changing careers due to the over-involvement in a narrow and not practical area. Other people who are smarter and more flexible usually choose to abandon PhD programs once they find themselves sort of stuck, and shift to more practical areas of programs with shorter training for the job market. It is painful, and involves recognition of the waste of the time already spent in the PhD program, but once they get over this and find decent jobs to establish themselves in a real career, they typically do fairly well and not regret the decision for a change. I have observed people who shifted from PhD programs in linguistics, literature, economics or other humanities to master programs of computer engineering or some other practical programs such as accounting, MBA, nursing, pharmacy, etc. Similar shifts happen to PhD candidates in math, physics, philosophy which happen to have no jobs in market either. A lesson learned from all these cases is simple: (i) do not enter a PhD program with no jobs unless this is the only vehicle or bridge to help reach your final goal, final goal being things like pursuing one’s true interests without the pressure to earn breads for yourself or family (e.g., your parents are multi-millionaires), pursuing academic career if you believe you indeed have a chance (but be noted that too many people overestimate themselves for this), using this as a bridge to go abroad or to immigrate (green card), using this as a buffer to keep the status between jobs, using this as a stop to buy you time before setting the final goal; (ii) in case you enter such a PhD program for whatever reason, try to get out of it as early as possible and do not be easily persuaded by your own inertia or hesitation, your professor’s nice words, or the brand name of your university: all this does not count if they cannot help you find a job to establish yourself for a decent career.
Having said all this, if you think at this point your pursuit for a PhD program in Canada helps you to get closer to your final goal for immigration and pursuing a career in North America (with which I agree, coming out of China is the first step towards the goal), go ahead applying. First, follow the application steps set by the university in general and by the department in particular. Meet all the deadlines, prepare for the tests if they require one (many programs in canada do not require GRE or GMAT tests, but some do). If you apply for 5 programs, I think you will get at least 2 offers of acceptance. It is also quite possible that you will at least get some financial support (such as tuition fee waiver). With careful plan, the chances of getting full financial support should also be there.
I think you can improve your letter by adding at least one paragraph on why you choose him as your advisor before you present your background. Say some nice words about him and his accomplishments. If you can discuss some of his work in more details, it will surely draw his attention. If I were you, for the initial contact, try to email him with shorter message instead of formal application cover letter. Once he replies you, you can keep the communication going by asking more questions, and showing strong interest in his work and it will be natural to indicate you really want to pursue a degree under his supervision and ask him for how you can better prepare yourself for that. In this electronic age, you should set up a personal page or LinkedIn account with your refined CV (put a picture or icon of yours in it), some of your select albums and other nice activities or aspects you want to help impress others. In your email, your application package, you always leave a link to your personal page. This way, when a professor or admissions officer examines your email or application, they can easily click the link to know more about you. The candidate and application will no longer be just an ID to their eyes, the real person behind has a chance to meet the decision makers.
That is as much as I can think of on this issue. Hope it helps.
In general, if your family can support you for the first year, you will be able to get multiple offers and be more selective on which program and which university & location you want to get into. If you entirely depend on the financial support from the university or professor to do the degree, your choices will be limited. In my generation, some very bright students had to enter a second-class university, simply because that is the one with financial support at that point (we call it 有奶就是娘).