As others have said, you should go to a bike shop.

For what it's worth, I have a 168 mm Romin, but I'm a bit of an anatomical weirdo and it's actually a touch too narrow for me: I'd probably be better off purchasing a woman's saddle given how wide apart my sit bones are.

Be that as it may, I recently took a chance on a Brooks B17 and I'm finding that it's wide enough and gives me the support I need even when not broken in. I'm capable of riding it for longer periods of time than I was with the Romin so it's staying.

If you really want to try a Romin, then get to a bike shop that sells Specialized gear and try one out. Many shops will let you return a saddle as long as you don't damage it.