Nick, this is a brilliant idea. Thanks for sharing it with us; I think I may steal it one day if I'm ever in a position to do so
Whereabouts are you located in Canada?
Here's some of what I can get for you. We're in zone 5/6, so it may take some time to naturalise to your climate.
Nick Kitchener wrote:Russian Olive
Blue False Indigo (I think -- it could be the other false indigo)
Aronia / Chokeberries (offspring of 'Viking')
Goji / Wolfberries
Hazelnuts / Hazelberts (from Gellatly Nut Farm just up the road, one of North America's premier sources of hardy nut genetics)
Black Walnut (again from Gellatly)
American Black Elderberry
I also can find wolf willow (Elaeagnus commutata, which is native to North America, unlike Russian Olive) and buffaloberry.
Most of these will have to wait until the fall, of course. Please don't hesitate to remind me come September or October if I don't remember to contact you by then!