so not what you are proposing but IMO

the best first float plane set up with ease of build....Goldberg Cub and Goldberg float kit with a 70FS. Perfect no brainer easy to build, set up already designed, great flyer at 76". I have had a couple. very durable as well.

if gotta have larger, hard to go wrong with Cub on floats.

if being first seaplane, start with something that you do not have a ton of time and money invested.

my thoughts