I am surprised that Parmaount Orchids has not been mentioned before this as they would appear to be Canada's largest orchid vendor, based on their orchid selection. Here is a link to their site.
http://www.paramountorchids.com/Main.html
My experience with them has been positive. Bryon, who handles the orders has been very helpful with any questions I might have (pests, culture, product).
Like some others their order system is dated.
My biggest concern with their listings is the size of the plant in the listing. For the most part there is no way to tell if the plants are seedling stage or blooming size ( no SS, MS, LS, NBS, or BS designation for most)