For many years I had a 9' Avon hypalon roll-up dinghy
. The floor was pvc slats joined by rubber hinges
like a roll-top desk tambour door. It was a real floor! The thwart seat and oars were the only removable parts. You literally rolled it out and inflated the two large chambers and the inflatable keel. I used it for 15 years seasonally in New England before I got a larger hard-bottomed dinghy
(that's another story). The roll-up still holds air after 19 years.
We started with a 6 hp motor, but downsized to a 4 hp, which was easier to ship and unship. The motor was clamped on a bracket attached to the stern pulpit when underway. The 110 lb. dinghy
--sans motor--was hauled up on the foredeck, deflated, and rolled up if we were traveling any distance over 10 nm. It helps to have an electric pump
, but it isn't necessary. After a few years of horsing the dinghy
over the lifelines, we decided it was easier to hoist it up using the main halyard.
The trouble with the roll-up was that is was a wet boat, having a low freeboard. We also had to be careful landing and launching on the beach. We added removable wheels back when they were called Davis "Wheel-Aweigh". We were getting older and this allowed us to pull it up the beach and not worry about sharp shells--and you do need to worry about them! We used this system for many years and it worked well.
Over the years we've had inflatable, hard bottom inflatable, and hard dinghies (Dyer Dhow). For your size boat, an inflatable that you can stow--preferably deflated--on the foredeck is what we'd recommend. An inflatable is much more stable that other types, but you have to protect it from shells when you beach it. You really need a motor, but a small one (2-4 hp) is all you need. If you intend to keep it for a long time, spend a few more bucks for hypalon and store it in its duffel out of the sun when you are not using it.