Could you order online from REI, and then return by mail if it's not comfortable? The cost of the postage is probably less than what it would cost you in gas. Also look at Performance for the same idea. You probably have a pretty good idea of what you want.

For my first Terry Butterfly (my go-to saddle) I bought it just ahead of a week-long bike tour and got the tour company to fit the saddle to the rental bike. I figured that if it didn't work, I would take the saddle back at the end of the week.

It worked.