Here are a couple pet supply stores in Sarnia that would probably sell what you're looking for.
http://www.petvalu.com/storelocator/...&state=Ontario
http://www.healthypaws.on.ca
There's another one called the Pet Food Warehouse, but they didn't have a website.
Wet is best for your cat, but some good brands of dry to supplement the wet (if you're so inclined) are Orijen, Innova EVO, Wellness CORE, there are tons of great food out there, just not sold in grocery stores. All the above mentioned foods are grain free which is much much better for your cat. You WILL notice a huge difference in his coat when you switch to a high quality food.