I just now saw your post, and while I don't have a Rafter S holster I've heard plenty of good stuff about them. You may have called them by now and answered all your questions, but if not I wanted to let you know that they do make other styles of holsters besides the ones shown on their site.
A poster on another forum had them make a pancake holster with a thumbreak. They already had a pattern for a pancake holster and they had no problem adding the thumbreak. Here's a pic of his fancy rig, I'm sure he wouldn't mind me sharing it:
Good luck to you and be sure to show us what you get!