[Fondueset]

Two suggestions - well three:

First I think a 75cm euro gun would do everything you want. Something like the new Omer Cayman.
I have a Riffe MT0. If you like mid-handle it's a pretty sweet little gun - though it won't float. Mine is rigged light with a 1/4x 34 shaft and two bands but you can put any combo on it. It's only 32 inches long without the shaft. 10 feet from the muzzle is not problem.
Last is a pneumatic - a cyrano 850 would do you just fine in those conditions.