Took two tours with Tour Guys while we were in Vancouver in late September: Gastown with Marla and Chinatown with Alex. They were both very informative, personable and gave great tours (Marla in particular was gifted in gathering us in to keep us out of the way of bystanders and I found myself saying her catchphrase "pretty good" for several days afterward!).
I would recommend doing these tours toward the beginning of your visit so you have time to come back and explore places that interest you. Oh, and ask the guides for recommendations if you're looking to find places to eat or things to do, because these guys/gals really know their stuff. Alex, for example, gave us a great reco on a Japanese ramen place (Taishoken, if you're curious) and Marla directed us to some tasty tacos (Tacofino, around the corner from the Gassy Jack statue in Gastown).
Heads up: you end in different places than you started (in Gastown, it wasn't that far but it was a fairly long walk for Chinatown), so keep that in mind as you plan your day.