I use Duluth Packs, my oldest is the #3, but on my last few trips I have used my Wanderer and Cruiser packs. I also trip with a wood canvas canoe so I like the look of them in my canoe too.
I have been blessed with a good back I guess, 70lb canoes and Duluth Packs are no problem even as I push 65.
3 trips across the portage is ok when the food pack is full, a week into the trip double them up and make two trips.
If moneys tight, you can't go wrong with a Duluth Pack, and the plastic liners are a good deal, double em up and your outfit will stay dry.