Ghosting is basically when the image meant for one eye is seen by the other. Usually most noticeable in high contrast scenes. Some people recommend reducing the gamma to help get rid of it.
With a 3D monitor you're going to get a 120Hz refresh rate, response time isn't anything to do with ghosting (just how often the monitor changes the image its displaying with an updated one from your PC).
Really I'm not too sure on this subject, my projector doesn't have any issues with it so I'll leave this one for someone else to have a say. I know someone on here has a 3D-vision setup with monitors, can't remember who though.