Join Date: Jan 2008
Location: Beaverton, OR
Bikes: 2013 Kona Jake, 2015 Kona Jake the Snake, 2008 Kona Major Jake, 2013 Kona Jake the Snake, 2006 Kona Kula, 2012 Ridley Excalibur, 2008 Surly Long Haul Trucker, 2001 LeMond Buenos Aires, 1984 Pinarello Gran Turismo, 1982 Trek 614, 1979 Austro-Daimler
Go to a Specialized dealer and sit on their sit bone measuring tool. Specialized makes saddles in several widths, and which one you need depends on how wide your fanny is and what position you ride in.
I've got the 143 mm Avatar, and I love it, but if it doesn't fit, it won't be great for you.
I wouldn't use a leather saddle because of the rain, but that's based on expectation not experience.