Anything that accepts a Trijicon RMR will work. They have the same mount pattern. CZ P10C, Glock 19/17, S&W M&P, all have optics ready variants that should accept an RMR. There are some Sigs and FNs as well. You want something with a fat slide (Not a 1911 or CZ-75 for example).
Do you have a gun that you can send the slide off and get milled? The optic will fit tighter for better security and will sit lower.
I have six red dot equipped handguns (two with 507Cs and two with 507ks, two with Swampfox Sentinals). Only one of them was optic ready (A S&W Shield that won't accept a 507C). Three were sent to Primary Machine for an optic cut and suppressor height sights installed.
I also like the rear sight dovetail mounted in front of the optic so it's still cowitnessed if I need it, but it doesn't clutter up my optic sight picture. It also protects the optic somewhat from blast from the ejection port. This is an option no OEM gives you.
Another weird thing is often the OEM optic ready variants don't come with suppressor height sights. So if you want to use your iron sights without removing your optic, you need to buy taller sights as well. Sometimes the better deal is buy a suppressor ready handgun (comes with the tall sights) and then have the slide milled with a simple optic cut.