Looking For Young Green Coconuts in Vancouver
What are you going to use them for? If you're just looking for young coconuts to slice the tops off of (and drink the coco water inside) then an Asian grocery like T&T or Osaka (in Richmond, inside Yaohan mall) should have young coconuts that have been trimmed down to a more manageable size.
This might be a long shot, but have you tried South China Seas Trading Co. on Granville Island? If you email them, they might be able to order in bulk for you (depending on how many you need).
(side note: there's also a fair amount of juicy coconut meat inside, just need to scrape it out with a spoon)