When I had my 09 exc I ran the stock caliper. With a 320mm rotor there was plenty of stopping power for the street. If your planning on lots of track days a caliper upgrade probably makes sense though.
I've never ridden supermoto but it's been on my mind for a while now as a fun track option. Currently contemplating whether to get a lightweight track bike or explore supermoto instead.
I always envisioned sumos on small kart tracks with lots of twists and turns. Is Grand Bend the most suitable of the tracks in Ontario? Are there any other smaller tracks that run track days that would suit sumos? Also, is SOAR the only (potential) racing option in Ontario?