The problem with wider saddles on road bikes is that the wider part tends to chafe the back of the thighs of the rider when he is pedaling.
The reason road bike saddles are so narrow at the back is because the rider's weight on a road bike is a lot more forward-biased, so not as much support is needed there.
For me, the solution was the Selle Anatomica X-2. It's a leather road bike saddle with a perenneal cutout to relieve prostate pressure.
The trick is getting a road bike saddle that's the right width for the rider's sit bones, but no wider.
That, and wear padded shorts or leggings for rides longer than a few miles.
I hope we're wrong and that that saddle works out for you swimmingly.