I like the Mirrycle mirror so much that I would cobble up an adapter to attach it where I wanted it. Easy for me to say since I have a friend with a machine shop in his garage. My next choice would be to use a clamp on aero bar mounted where I needed it that the quill fits into. Expensive unless you happen to have a set laying around.
http://www.hostelshoppe.com/cgi-bin/...sory=987268561
Maybe this is something you can use. I haven't tried it and would be concerned with the long stalk vibrating, assuming you'll mount it sideways, but you can always contact them and see what they say.