Hey hey,
You're looking at either the Rex or the Courthouse. The Rex is...well, everybody who goes to Toronto goes to the Rex man. You've probably been there. That night is the Brandi Disterheft Trio (really great local basssist) followed by Jim Hillman's "Merlin Factor" out of Montreal. Two of the guys playing in this -- Dave Restivo and Rich Brown -- are absolute monsters. This'd be a great night.
www.therex.ca Unfortunately, as you'll see below, it's pretty much your only option...
The Courthouse is a new one, somewhere downtown -- it's an expensive place too. Pretty good acts I understand 6 nights a week, but you aren't gonna get a $5 pint there that's for damn sure. Unfortunately it's closed for a private party the night you're here.
http://www.liveatcourthouse.com/
There's also Trane Studio, which normally has pretty good music on. Strangely enough, I see they're hosting a book launch that night?

Maybe this is something you're interested in.
http://www.tranestudio.com/
Other than that, there's always the venues El Mocambo, the Cameron House, Kool Haus...mostly not jazz though. If you're up for comedy, Yuk-Yuk's might not be a bad idea.