If your trip isn't necessarily about herps I fully recommed the Vancouver Aquarium! It is a great place to "lose yourself" for a couple of hours. As for The Zoo, I've not been there, but, I've also not heard too many good reports about that facility. It's not even close to Vancouver (downtown, where I live) and takes hours to get to by public transit (we got rid of our car when we moved here from Whistler).
Again my best advice is to give Renee D a private message (PM). She works in one of the better pet stores in Vancouver, and breeds many animals. She also sells to many of the pet stores in the surrounding area, so she has many contacts. If you have any problems getting a hold of her let me know and I will tell Renee about this thread.
Best of luck, and go to the members section to get ReneeD's PM, she is a member here.