My favorite supplier is Revival Animal Supply, I love their fast and great service. I don't know if they ship to Canada.
I made my whelping box with a Rubber maid container I love it because I can bleach it before and after each use. Here's a couple of pictures of my setup..
http://i126.photobucket.com/albums/p...2/IMG_8681.jpg http://i126.photobucket.com/albums/p...Picture109.jpg http://i126.photobucket.com/albums/p...Picture160.jpg