I can just echo what others already said - buy whatever feels comfortable.
I've tested saddles by buying and returning through
Wiggle - i.e. bought a bunch of saddles, wrapped rails in some electrical tape, fitted to the bike, gave them a test. Following that, made the choice, unwrapped the tape, gave them a good wipe to make sure there were no marks and returned in original packing. Selle Italia saddles are very easy to put back in original packaging without ripping it apart.
You can also call your local bike shops and see if they offer something like a 'saddle library' - where you can leave a deposit and test a saddle.