Former N. Vancouver resident here.
I know the thread is a little on the old side, but, if you're still looking I would strongly recommend N. Van over Tsawwassen. I was able to go virtually vehicle free while I was a student at the BCIT Marine Campus.
The city is very bike friendly and has easy access to the Sea Bus passenger ferry and both the Lions Gate and Ironworkers Memorial Second Narrows bridges. There's also access to the Seymour Demonstration Forest which has an AWESOME and very wide (almost 6 meter wide) bike path, though the final bit to the salmon hatchery is a well well maintained gravel path Longer rides into Vancouver and Burnaby from N. Van are easy too, which makes for a nice afternoon ride, or longer if you're so inclined.