As far as I know there are no commercially available folding wheel setups that will roll across a soft sand beach for a boat your size. I looked hard too. I made my own set which is what you are probably going to have to do, or have someone else do for you.
Even then you are going to want to put your boat on a diet. I just switched to a smaller removable fuel tank, that went from an 11 gallon US tank to a 6.5 gallon US tank. Made my anchor setup removable and am working on having all my electronics including the battery, mounted in a tower, become removable with a handle.