FWIW, I went from a 155 Lithia to a 155 Jett to a SI Turbomatic because I need a saddle with a pronounced T-shape, a narrow nose and a cut-out that's wide in the rear and long in front.

The Turbomatic is just slightly narrower in the rear than the Spec' 155s, so if you're on the edge of needing a wider saddle, that one won't work for you. It's also pretty pricey. But if you think you could get away with slightly narrower, you might see if you can find one to try.