I also would suggest making a Schneider plane.
I did several Schneider planes, some of my own design (savoia S.21, the real one, not Porco Rosso, Savoia S.65 in two sizes, Bernard HV-220 and -320), some in Kitform, like the no longer available GDH Curtiss R3C-2.
The most fun I ever had with model airplanes is with Schneider planes, as you can take them hard and fast, and even more fun is when you have some chaps around with the same "gap in their mind" to make a race. Here the 3S lipo class around 2-2,5kg seems to be the best compromise between having a plane that withstands the weather best and being economical (cheap hardware).
A Curtiss R3C would make sense (the GDH never flew off water), or a Supermarine Sea Lion flying boat.
If you are interested, I would be too. Please feel free to contact me