My vote would be for wider beams. That would be the best potential for a "different" boat, regarding potential speed improvement.
My experience with the Hobies, 18 and 21, was that the wings did not really add much in the way of speed. First, with the wings all you are doing is adding leverage when the wind conditions are high enough to justify going out on the wings. In most conditions it was generally thought that the wings only added weight, no real advantage.
Now when the beams are extended you are not adding weight (much) but you are immediately changing the leverage equation. I would guess there would be a big advantage to that, so I would start there. The boat I sail has a 16 foot beam, and I am continually amazed at the effect of leverage.