You know, there's a surprising number of those places around, and they pretty much - as far as I can see - charge about the same, so you may want to check the yellow pages (try looking under "Promotional") and see who is the closest.
Having said that, the place I have used for years for jerseys and hats for my hockey team is The Next Trend Designs (1200 Aerowood in Mississauga, near Dixie and the 401; (905-629-2666). They have every item of clothing imaginable to piut your logo on, and I believe can help with artwork if you don't have it. Good luck!