Check this one. Ottawa is at zone 5. You have to choose the tree has lower number than it.
And by the way, if you do not plan to use pesticides at least once every month. You may get nothing. Insects get them before you. You may have many fruit for show, but they fall to ground before mature with a small hole on the skin. The center is a worm house. You may get lucky some year. They said if there is one unsprayed tree in few hundred yards, the insect is uncontrollable. I only get one apple from my apple tree last year without spraying.