Check out the link in my sig to my tires... they're supposedly mud/snow rated, but I don't know if I believe it, 'cause I took them off before it snowed. They were great during the spring/summer/fall though. I suppose they'd be fine in the winter (but I don't know about Canada) if they were on 15's or 16's with a little more flex than mine.
Otherwise:
www.tirerack.com or
www.discounttire.com is where I would look.