Canadian Tire is not recommanded place to shop for these items. On the other hand, when we talking abour the engine, most of the Mfrs are using Briggs & Stratton® engine since Tecumseh went bankruptcy... there are the Honda engines (less noise, but much more expensive), or some other brands. But Briggs..got most of the market.
The most important things is not to have too many cable controlled accessories...expensive to repair breaks more often...
thickness of the body steel
steel chute vs plastic...the longer it is the further the snow goes..also matches the impeller rotation speed
Toro is the best. however, it is too expensive. The less expensive but with higher quality is the Ariens (not the sno-tek series).
Homedepot only carry the 28" one, you have to go to some local Ariens dealer if you want the 26" one. They have the same engine, but 26" one is arround $150 less than the 28" one.