If you only had 1 choice, then I would say Jiu-jitsu is the way to go. Especially if you're fighting a bigger/taller opponent. Basically you want to close the distance, take him down and submit him. You don't want to be standing there trading punches because your reach will be shorter. Also, it's usually not realistic to be able to guillotine-choke someone who is taller than you. It's proven through the Gracie family. There's one dojo on highway 7 and Leslie or Bayview (can't remember now, it's been so long). But it's so prevalent now that you shouldn't have any trouble finding these businesses in general.

