I,m using a set of plastic GeeBee floats that came on a used Cub . They are installed on a kit built Lt 40 thatI maiden just today, as a matter of fact. Also have a CG Cub on homemade skis and they work well also. But as goirsh said, floatsare the best and they serve 2 purposes, water or snow. Also if your working off the snow , the plane sets on top of it nicely.
I followed the suggestions of others here on RCU and balanced by adding the weight to the floats, then when you put the landing gear backon there is no need to rebalance.