Hey Nick -- watch eBay.ca for them. Or check out your local Buy and Sell, Craigslist, etc. They are hard to find commercially in Canada, but it seems there are lots of guys selling them privately.
I also bought some from Alternative Beverage (http://www.ebrew.com or http://www.homebrew.com -- same store), based on the advice of some other Canucks here on HBT, and was really pleased with them. They shipped USPS so it was cheap and no brokerage fees.