Part of my fly fishing attire has always been a vest, and that's when wading or in the canoe. No doubt carry more then I need, but better to have carried the jun... (eh, stuff) not using all of it rather then being a considerable distance away with a need and not having it. Also have a fanny pack that I might use for a quick short distant try, or when it's hot and the vest would be real uncomfortable. Wading the smaller streams around here I do not use a flotation device ~ for the canoe use the simple cushion floaters, but again, not all that depth of water.
Now I have two vest, the regular run of the mill 50/50 cotton polyester (like for use as listed above), and a special one I use for large, fast moving, and especially strange to me waters. AND, in the canoe when crossing over deep water like a lake ~ and that vest is a Stearns and it has a CO2 cartridge to inflate, plus has a hose where one could do a huff & puff job instead. This vest is heavy duty and I especially like it for real cool weather. Don't know if the Stearns vest would be what you might be looking for, but let me say I've used it for at least 15 years now and I like it.