Hi. Decide how much money you can spend and what you want to do with a firearm before you do anything else.
'Which companies' covers a lot of different stuff. You thinking retailers or makers?
For the former, forget any American shops/sites. And don't compare U.S. and Canadian prices. Costs a lot more to do business here, there far more government interference and our market is 1/10th the size of the U.S. market.
For the later, there are virtually none here. Lots of builders and a few U.S. owned factories, but nobody makes firearms exclusively for the Canadian market.
Some of those U.S. manufacturers are selling on their name. Colt is one. Nothing wrong with the stuff but the prices are higher because of the name.