I went with these:
http://www.campingworld.com/shopping/item/xlr-ratchet-clip-on-tow-mirror/55143
Yes, they're strap-ons, but I have crome mirror bezels and the plastic hardware and stretchy straps didn't leave any marks on them at all. My only complaint was the 'moaning' noise they made at-speed (they were NOISY!) but in terms of function, they were excellent.
Any of the ones that stick to the mirror glass itself will be pulling on the little plastic gears inside the mirror that drive the mechanism. They are not engineered to take those sorts of loads and will quickly fail. I would not recommend those solely for that reason.
Good luck!