Spec' has several saddles that are similarly shaped but a lot less cushioned than their so-called "comfort" saddles, and they all come in 155 mm. If you liked the shape of your Sonoma, from least to most cushioned, you might try a Ruby, Jett or Lithia.

If you order one online, there's a 30-day return period; you might be able to talk a LBS into offering you the same deal.