I was buying Mountain Dog Food from a guy in Kingston..they also have cat formulas. If you go to the Mountain Dog Food website, I'm pretty sure he's still on there. I think of all the commercially made foods their's is pretty reasonable in price and they sell in larger quantities than the ones you can get at petstores. You can likely get a few samples to try as well.
I would check with Greenlees for stuff from the butchers.