Here are three links to three respected online Canadian retailers! Buy in country if you can! Support Canadian airsoft retailers!
http://www.airsoftparts.ca/store2/
http://www.capitalairsoft.ca/
http://www.velocityarms.ca/
As for importing airsoft into Vancouver, its essentially the same as all over Canada, risky business that is an at your own risk thing. The shortest way to explain it is that essentially airsoft kinda falls into the group of "replica" and replicas are prohibited devices in Canada. You are still welcome to try, but it is at your own risk and understanding that other issues may arise if you do attempt to import an airsoft gun. The majority of the time Canadian border services will confiscate and destroy them, and sometimes you are even added to a black list for which every parcel you order is heavily scrutinized, be it airsoft, clothing or whatever.
If you are interested here is the long winded and very detailed and highly recommened that you read version of how airsoft in Canada works.
http://www.airsoftcanada.com/showthread.php?t=51609.
Aside from the short list of retailers I posted above this website also has a buy and sell section which can only be accessed through age verifacation. What is age verifacation? Age verification, is where if you are 18 or older you can meet with a volunteer representative of this website who will meet with you in person, there is no way around this, no phone, no webcam, in person only, where they will require to see a legitimate piece of photo identification. After the process is completed, it can take sometime as this is all volunteer work, you will be granted access to this websites buy and sell section, where you can find both new and used guns, for fair and competitive prices. Although its not always the case, it is sort of an open market.
Cheers.