An Assymetrical spinnaker can certainly speed up a long off-the-wind run, the principal advantage of it is that it requires much less gear to effectively use than a conventional sym Spin. No pole, or pole lift simplifies things and keeps the decks clear.
As a downwind sail, however, it has definite limitations. Typically meant for broad to beam reaching (and some flatter shapes for wind sightly forward of the beam) the lack of a pole to project the sail outward means you are sailing higher angles to keep it full, subsequently travelling further on a dead downwind leg. This can actually mean more gybes as you make your way to downwind.
A snuffer makes the sail very managable during hoists and douses, but if you are truly doing all the sailhandling you will still need a good autohelm to keep the boat on track as you set up the system for the hoist, and raise and lower the snuffer.
Unlike a conventional spinnaker, though, the A sail can be gybed from the cockpit. But there is a lot of line to pull, and again you'll need someone/something to steer the boat through the gybe while you're doing that.
Would suggest adding a proper spinn halyard above/outside the headstay, using a jib halyard will lead to chafe as it crosses under the headstay gybe to gybe.
As to sailmaker recommendations, I'm sure someone local will pitch in here. Good luck, I think you will appreciate having the sail.