Hello Old n Slow ,
The length of the floats should be approx. 75% of the lenght of the fuse measured from the hinge line of the rudder to the front of the propeller thrust washer. They should be spaced apart at approx. 25% of the wing span. The top of the floats should be at about 2 degrees positive incidence to the wing. The step should be at or very near the center of gravity of the plane.
I can say with little doubt that if it flys it can be put on floats. Take a look at this web site
www.geocities.com/planefunfloats