This will be an interesting project. The swoose kind of reminds me of the old racing seplanes. See below supermarine S6.

Perhaps the best approach will be to build one of the short kits and then weigh it. Then the floats can be made. I do not have an idea how much it will weigh at this time. I expect it will fairly heavy as I intend to use a 4 stroke and wouldn't the fuse/wings etc. require waterproofing?

Can seaplane make custom floats and make them so the plane will float correctly for my application? I will see if I can contact him.

Mitch