Good advice!
We've been using the Seda for years and I've yet to find a lighter, more comfortable PFD.
If you have any trouble finding a PFD that doesn't ride up when sitting down you may want to look at the PFD's designed for kayaking, which are usually shorter in the torso.
I agree with getting the best you can up front but would add that you may want to go with a bright colour. We have a rule now that says if you take off your PFD during a break it goes into the canoe, no matter what, and not on the ground. We've lost a few drab colour PFD's over the years when they were taken off and left on the ground, which, if they were a bright colour, may not have happened.
It also makes them easier to spot when loading up at the end of the day if for some reason they had been set off to the side...........
"Morley, you beat me to the colour issue, only for a different reason, by just a few minutes."
Jack