in the 80's when i was actively full time pro as both a musician and photographer,we had coverage with prudential . also another one with Wawanesa (spelling
) it's been a long time, so they make have been bought over.
but i would ask a bank manager of one of the 4 chartered banks (TD RB CIBC BNS)
and if they don't handle floaters for pro equipment, you could ask them to recommend a reputable company who does.
if i recall, it was just an all risk floater for professional equipment, added to my home insurance.
UPDATE:
or consult CAPIC
http://www.capic.org/about.html