pmurphy

Unfortunately you are colder than me - Vancouver - so most of the BC suppliers I know of only have the basjoo or other less hardy plants that you will have to over-winter.
My best recommendation would be to contact Mike at Welcome to MontrealPlants.com!
He deals mostly with palms - as his website shows - but can special order many types of bananas. His plants prices are very reasonable but shipping can be expensive to BC. I had one shipment of palms from him last year and was very happy with both his service and his product. This spring I have on order from him gran nain, mekong giant and rojo.

If you are looking for ornamentals that you will have to overwinter, check out:
http://www.tropic.ca/bananas/ - not sure if he ships
http://www.hawaiianbotanicals.com/ - I know they will ship
They are both located within the lower mainland
There is also one nursery in PEI that I have yet to try but they do list some types of musa sikkimensis as available, and they do ship within Canada
http://thehoneytreenursery.com/Exotic-Trees--and--Plants.php

Good Luck!