http://www.gamespeopleplay.ca/home.html (Never been, just looked it up)
Have you considered custom making one? Some places, all you need is a high quality picture and they can make one for you.
http://puzzlesprint.ca (Just an example)
Unfortunately, there doesn't seem like too many places left that carry them. Online really is one of your best bets, but I have no idea on a good reputable one, sorry.
BUT, I would give amazon.ca a try. Varied sellers, so it's hit or miss on occasion, but payment is secure (which I presume is a concern of yours?)
A completely different option is maybe join a hobby group/meetup.com for jig saw puzzles and do puzzle swaps? Kijiji is another option as well.