Your sit bones are only 110 mm apart, you should get a saddle that's only 131 mm wide. A wider saddle might not be a better fit especially if your sit bones end up right at the edges of the cutout. If your saddle fits you perfectly it will sort of disappear from your conscious thoughts while riding.

Just so you have something to compare, my sit bones are 130 mm apart and my Selle Italia Superflow is 143 mm wide. That means my sit bones are only 6.5 mm from the outside edges. But the saddle fits me perfectly while riding.