7TFord,
There are lots of places to get Redline in the Toronto area, but seeing that you're in Muskoka, I'm not sure how often you make it down here (if at all).
There is a small motorsports place next to York University (South side of Steeles Ave, just East of Keele St). I don't remember the name, but it's visible.
There is also a place in Mississauga that I usually buy my stuff from. It's on South Sheridan (service road), on the south side of the QEW, in between Southdown Rd and Winston Churchill Blvd. It's called JRP.