There is significantly more parity between Canadian law schools - that is to say that there are no truly "bad" law schools, and that you will find a job in almost any region with a LLB or JD from any Canadian law school.
Also, the Canadian legal market is significantly smaller than the American market with fewer grads produced per annum. The implication is that as a lawyer, you are still guaranteed a pretty prosperous career in Canada with a lower chance of post-graduation unemployment (though peak salaries tend to be slightly lower than in the US). The restrictions of graduates are largely an artificial product of the CBA and other legal professional associations, not excluding Canadian legislation that requires that law schools be affiliated with an accredited university. (also the process to register a new law school is a long and arduous one)
As for your second question, there are differences in how well reputed Canadian law schools are for different legal concentrations. For example, Queen's is particularly well known for it's Criminal law program while Osgoode focused more on the Administrative and Public law fields. The western provinces (particularly Alberta) tend to specialize in the energy driven (oil) businesses. Dalhousie and UofT are particularly good for IP. UofT will guarantee you a well rounded education in any legal field.
That being said however, a Canadian JD allows for great flexibility to maneuver within the legal market. You graduate as a general practitioner (assuming you pass the bar requirements) and are licensed to practice in any field. Your post graduation job will likely determine which fields you eventually specialize within. Choose OCIs carefully.