Have you tried Selle Italia? I have a skinny ass and got measured up using the
Selle Italia IDMatch system as an S1 fit. I bought an SLR Titanium (TT) which is lightweight, has minimal padding, and is flat and sleek looking with no cutout. I find it very comfortable. If you have a wider ass and are more flexible at the hips, their system will suggest a wider saddle (e.g. Flite) and one with a cutout (flow and superflow). Fizik Arione also works well for my ass shape, and I have another Selle Italia saddle, the C2 Genuine Gel, which turns out to be an S1 and has also worked well for me.