I'm not sure if the product I'm looking for is like looking for a needle in a haystack, but it's worth a shot:
What I'm looking for is a laptop backpack that has a pass-through slot on the back allowing me to attach it to the handle of my rolling suitcase. To help matters farther (or complicate them more, depending how you look at it), it has to be available in/to Canada and not cost an arm and a leg (ie: <$100). Something along the lines of this bag but in backpack form:
I know MEC has
a series of backpacks that are exactly what I am looking for, but I'm not too fond of their construction, nor of the fact I have to turn the backpack sideways to put it on the suitcase.