That's a good find on the float it looks like. I'm like you and think a floating dock is a better way for me to go and something similar to what you are describing.
It looks like these are rated for 500 pounds. I know others have used the plastic 55 gallon barrels which will still be cheaper but this might be the "better" way to do it.
I will keep watching for the others to chime in.
Dave
