I have one that mounts to your hand. I don't know of any that mount to the gun. On the plus side , I can use it with all my semi-autos, not just the 1911s.
Actually, I have an old one that I purchased many years ago. It is a hard molded plastic that snaps on the frame. Drop me an e-mail if you are interested.
Rebs - the top part sits up just high enough to not block the sights. As far as marking the finish I can't say since I had a stainless 1911. It is possible it would but don't know. It fits under the frame below the barrel and on the side by trigger guard.
FYI I've just looked at it again and discovered that it has a small crack in the catcher part but I don't think anything serious. I'd send a picture but being all black it tends to blend together!