I have a full set of the factory gray vinyl cushions, would not have bought them, except a member on this 'site sold them to me for a C-note, and I installed the snaps on the fiberglass. They fit great, and look great, and are for times when I want the boat dressed up, and on dry days, not to be left on in the rain etc.
The closed foam cushions pictured above are the everyday cushions I use most of the time. SIx panels cover the cockpit reasonably, three seats, and three backs, two sets for the two sides, and another set one across the entire back seat. I strapped them together with webbing, using the double-D plastic fittings in between to act as a hinge, which keeps the seat and the back together, but easily folded up or down and stored without removing the straps. The strap tails have the typical snap buckles to fasten the seat backs to the struts of the bimini, and around the Genny blocks, and the mid-stanchions, to keep the cushions in place. Then in places like against the cabin wall, or where extra padding is needed, of course the regular flotation cushions are always nearby. I forgot where I bought the long foam cushions, one of the major marine suppliers, or from a large boating company online. The best thing is they are almost indestructable.