If I understand correctly you're wanting a serpa "push button" and a thumb break on your holster. Is that correct? If so, that's an awful lot of retention to work through before you can draw your gun.
I've never heard of such a holster and very much doubt that you'll find one out there. Custom shops will usually modify their designs to suit, but I don't know a custom shop that works with the Serpa retention system.
Bianchi integrates a retention device similar to the serpa on some of their leather holsters, but I don't see a model listed for your Ruger. Even if there was one, you'd still have to convince them to add a thumb break, if they're set up for customizations, or have someone else add one aftermarket.
I'm afraid that what you seek simply does not exist. But best of luck on your search.