Quebec city or Montreal?
Lots of choices can't help with outfitters, there will be a variety in many places
And How much driving? to a site to paddle? (you can add a lot of K's here.
Do you want a true Wilderness experience?
What time of Summer? Bugs can be a real issue in eastern Canada and if you never been exposed to black flies, you may encounter a reaction to their bites.
Just too much stuff to through out a few suggestions. If you had a wish list like say a Group of seven location or Say a Location that Grey Owl paddled at then it might be a start.
https://www.historica-dominion.ca/conte ... s/grey-owlor even a specific Historic fur trade route.
It will be a tough choice.
Jeff
oops edit add on...Pictogragh sites...
yeah lots to chew on!