since your handle includes the stem ortho- and you can bandy about terms like perineum, I'm guessing it won't be too hard to find a colleague who can accurately measure the distance between your ischial tuberosities (in mm preferably). Armed with this info and a tape measure, you can start hitting the shops and ruling out a few models that would clearly be too wide or narrow for your anatomy. Then, ask if the shops have demos/takeoffs of the ones that look like they may work, mount 'em up and take 'em for a spin. it would help tremendously if you are properly fit to the bike beforehand to eliminate any vagaries of up/down/fore/aft saddle position.
That being said, i will also echo Dave Hickey: Which SSM saddle is almost-right?
EDIT: Unless, of course, you're an orthodontist. Ass-grabbing is not as much of an everyday occurence in that profession.