Have you tried the Specialized Jet? The Trek store has that nice measurement device for your sit bones and they measured me and sold me the Jet. I LOVE it, it has the cut out just where I need it. For me a firmer seat with a cut out works best.

Oh and I agree that the angle of the seat position is key. I got a leveler and made mine exactly level and that helped a lot. Supposedly men do better with it angled up but women need it more level or even a little downward. I find though if it's too tilted down I move around too much and that is why I like it level. I suggest playing with the position of the seat, not just the purchasing of the seat.