The San Marco Regal was a good choice; it's what I use on my fixie, and I ride the fixie on randonneur brevets. Of course, everyone's sit-bones are different, so there's no absolute right choice. Just a couple of points:
- the Regal is not unpadded leather, like a Brooks. It's a padded, leather-covered saddle over a nylon base, like all the other non-Brooks saddles. However, for me, it's way more comfortable over longer distances (200 km +) than the San Marco Era I used to use.
- the shorts you are wearing are a confounding variable. You have to make sure you test the saddles wearing your most comfortable shorts. The process for doing this is the same as testing saddles - keep trying different shorts until you find one that's really comfortable, and then go back and buy several more!