If you're going to be float fishing in 8 or more feet of water you are going to want to use a polaris float, or a sliding float with a float stop, if you don't have a long fishing rod.
It would also depend on how far out you want to fish, how windy, and how choppy the water is, on selecting the right float.
I have a lot of succes with "The Lift Method" of float fishing.