What handguns are suppressor compatible?

The answer to this question is too broad to give. Most any handgun can equip a suppressor if it has either a threaded barrel, or enough of the barrel extending beyond the slide to mount a clamp-on style (which is generally a bad idea, but that doesn't stop some people.)

About the only king of handgun you really can't put a suppressor on is a revolver. Not because you can't physically do it, but because the gap between the barrel and the cylinder makes doing so pointless.