http://www.headshotsrentals.com/ <-- Proshop, good rentals and they deliver and pick up too, good but small used equipment
http://www.vistek.ca/ <-- Proshop, rentals, film, paper, chemistry, equipment
http://www.henrys.com/ <-- same as vistek; large selection of used equipment, multiple locations
http://www.downtowncamera.com/ <-- has paper, chemistry and some film; they will annoy you by asking why are you still shooting film since digital is better
http://www.adencamera.com/ <-- Prosumer level; decent film, paper & chemistry selection
http://www.filmplus.ca/ <-- Props for studio
http://www.eightelmphoto.com/ <-- Small selection of interesting equipment not found elsewhere
http://www.spectrum-studios.com/ <-- Inexpensive studio rentals, plus Genn has lighting equipment kits for rentals
http://www.torontoimageworks.com/ <-- Decent selection of film, darkroom rentals
http://www.pikto.com/ <--The place to find all the Toy Cameras and LOMO products you want; workshops; located in a very hip and trendy part of town
Nymoc (416) 465-1929; 24 McGee St <-- place to get alternative chemistry
Elpro (416) 348-8600, 3 Elm St <-- place to get cheap prices on darkroom supplies as they are geared toward students
http://www.gallery44.org/ <-- Just check this place out every now and then; membership is cheap and gives you access to a fantastic darkroom
http://www.elevatordigital.ca/ <-- You MUST visit this place; ignore the grumpy old man called Bob behind the counter - I hear he's a decent printer
There is not a good proshop in Toronto for studio lighting - selection on display or for demo is VERY limited. Actually, best selection is the rental departments at Headshots and Visteks. At least you can try equipment out before making a purchase. Most lighting equipment is bought from the US. The retail supply is controlled by a small group of wholesalers who have the crappiest marketing on the planet - which is why most Canadians buy their gear from the US.
Hope this helps.