Yes, the beams will fit perfectly on the 14 pylons and you can use the 14 side bars to connect them. You will have a much larger span between the trampoline pieces running down the center of the tramp.

I have thought about doing it, but I end up with the conclusion that if I wanted to make the boat wider, I might as well go with a Hobie 16. I would be adding extra weight to a boat that doesn't like a lot of weight and it would take a complete set of custom rigging to get the boat going. You would also need a H16 crossbar for the steering system.