BAT shows a rear brake hardware kit on page 7 of their catalog. Part # K420K6 for $20.75.
I don't know how hard it would be to have it sent to Canada but you might try calling them at 941-355-0005 to confirm that it includes the boots and see if they have shipped stuff to Canada and know the drill.
As someone already posted, their URL is
www.batinc.net You will need to download the catalog to view it. I did not find anything from the other link to SP Motorsports for rear brake hardware.
I doubt that you will do any harm with a torn boot for a few days but you don't want to leave it that way through the winter. It is something that you need to fix, but it isn't an emergency.