The first thing you'll need to decide is how much weight are you going to be hauling. Persons & gear, all new boats/canoes will have a plate listing the Max. Capacity according to USCG guidelines. I've trapped some from my 10' alum flat-bottom. It's a narrow boat, around 3' wide in the middle, in calm water it will handle 2 adults, but it rides pretty deep, around 8". Not sure what you guys are calling "portable"? We used to sell Coleman canoes and Crawdads, I can pick up a 17' canoe and load it onto my truck rack alone. I've paddled my 15' canoe a good bit, I bought it in 1985 (just before the flood) it's been well abused and still doesn't leak. Old Town makes a better canoe, they are made of a plastic/foam, really comfortable to ride. Coleman's are plastic. In our rock bottom streams an aluminum canoe won't take the abuse, compared to a plastic one. I can stand up and fish from my 15' canoe, it's more stable than the 10' alum flat bottom.
Forgot, we have a local outfitter that rents canoes, each fall he'll sell off 25 or so canoes. He has mostly Old Town canoes now, he sells them for $100-150 used.