We're using a 7'6" zodiac with a slatted rollup floor. Serves the purpose though our 10 foot kayaks are our primary shore transport. Nice to be able to roll it up and bag it below when it's not towing conditions - keeps the decks clear.
You're not likely to plane very well with a small o/b anyway so the lighter less stable bottom isn't much of an issue to us.
It just might be more economical and easier to stow a kayak on deck. Not sure how much room you have on the for'deck but I can stow/launch my 12 foot kayak on/from the bow in less than two minutes. I use nylon ratchet straps with hooks that go through the toe rail.
Getting in and out can take practice. I would suggest taking a kayak lesson just so you know how to get out of trouble. Otherwise its a fast ride and the current/wind are not much of an issue. Very beach-able too!