I was thinking, essentially, all I need is a pair of flotation chambers, that are cylindrical, and angled higher in the front than the back. So, how about a pair of 6'x6" sections of PVC pipe with the ends capped and glued, and the outrigger struts of 2" Heavy walled PVC, and attached to the boat at the aluminum crossbraces with zip ties. The idea is to have them be securely mountable, but easily removable for trailering the canoe.
They will need to be wide enough from the rails to allow for oars, since I also have the boat set up with oarlocks for rowing like a single racing scull shell for exercise for nonpowered trolling on the ICW. The width will also need to be there for stability with the outboard running....a 2 1/2 HP outboard will really kick a canoe along fast in relation to the hull design and it's not a Gheeno with planing chines for stability, but will be as fast as one. My canoe isn't a flatback, it's a double ender classic canoe.