I don't know of any that are only 155 mm wide. (cuz my sits are wider than that and I've only investigated ones that would fit me.)

The ones I like are the Brooks B66, B67, B68, and B72. They are very sharp "T"s, and legs slip nicely on the sleek leather so I've not had any chafing yet.

Some folks might not consider Brooks to be performance saddles, but you sure do see a lot of serious cyclists here in the Seattle area who have Brooks.

Maybe take a look at the Wallingford site www.wallbike.com and compare the tops of the narrower racy saddles to the saddle you have now? I know a few women who really like the B17 and the lighter racy versions of it, but I've never ridden one.

(about the only saddles I really investigated are Brooks, sorry, I've got limited knowlege!)