If you've got a car, you should be able to find someone quite easily. St. Lazare/Hudson is super horsey, and not too far a drive from town especially if you're okay with living a little farther west (NDG area, maybe). I don't have any specific names, but there are a few Quebecers on the board who might be able to help you out! I lived in Montreal for 3.5 years (Concordia, not McGill!) but I had no car, and there are no barns accessible by public transport that I could suss out.