Cub v 172
I saw that you were planning to take the wife in the 172 on floats.
I would check as when I did my float rating in the US I was told that the 180HP 172 was a little underpowered on floats.
I can also second the suggestion to use the SuperCub for fun, 150 or 180HP were great fun - as was getting my largish frame through the door.