I agree with Jim. You have classic tail-heavy characteristics. As a general rule, but not all the time, float planes need nose weight. If you plan to ever fly it on landing gear, put the weight in the floats. Many planes with added floats need additional fin area to compensate for the forward area of the floats.

I had some tail dragger floats like that and loved them. They were great for touch and goes. I also had an Uproar on floats. Great flying plane.

The only thing I would change on the Uproar kit, besides the goofy ailerons, is to put the hatch on top instead of the bottom.