Rupert,
What’ll work best for you depends on how many people you expect to carry, your fitness and energy levels, frequency of use, and how much you want to spend.
I’ve had flat-bottom inflatable dinghies (the cheapest route). A bit hard to row, very stable, work just fine with a small outboard or electric motor.
I’ve also had v-bottom, air-floor inflatable dinghies. Much more expensive, row really well, motor extremely fast and well, not quite as stable but pretty good. You can buy very good after-market skegs for them that protect them quite well if landing on a rocky beach.
Both of the above will weigh in the 60-75 lb. range, and will deflate and roll-up into a package you can bag and stow in a cockpit locker. There are electric air pumps that will connect to a 12v battery and inflate/deflate them very rapidly, or you can get some exercise hand-pumping that I minded less in my 30’s than I do now at 70.
I’ve also had polyethylene hard dinghies. Walker Bay used to build them, and I think West Marine still has a manufacturer that makes approximately the same boat for them to sell. The one I had rowed well, motored well, came with a sail kit and was a lot of fun to sail. Not as stable as an inflatable, a lot more weight. Those get over a hundred lbs. and aren’t fun to carry by oneself. The boat I had it for had davits.
There are also a number of other alternatives. I used to have a Tinker, a British rigid inflatable that also happened to fold. You could deflate the tubes, remove some pins, and hinge the front half of its fiberglass hull over to fit inside the back half. Like the air floor, it rowed and motored really well. Like the hard dinghy, it came with a sail kit and was a lot of fun. Folded, it could be stored on deck. It weighed more than anything, though, and the athwartships components that allowed it to hinge really interfered with the ability to move around in it.
I’ve seen recently a number of inflatable catamaran designs that look very interesting. If I needed a dinghy, I’d personally be interested in them but I have no experience with them to offer you.
I know a number of Nonsuchers use a system which allows you to tow a dinghy very close to the boat transom with the near end lifted out of the water. Here again, I have no experience with that, so I hope one of them speaks up and tells you about it.
There’s always the approach of getting any of the dinghy options and towing it on a long line.
– Bob