Steak qualities/beef grades in Canada?
The grades that you would be interested in, that are available in Canada, are:
Prime, AAA, AA, and A

See:
Beef Grades and Comparison with US Grades 

You can get Sterling Silver Beef in most grocery stores and it is either Prime or high quality AAA. It is also aged for 21 days. 

You can also order Prime on-line or ask your favourite butcher.