I bought one from Tower Hobbies. Uses 4 screws to hold it down. Mounts are adjustable. They claim it'll hold anything from a .049 ( I THINK!) to a 1.20. Have trouble getting mine to hold my GP 074, but it works really well on the bigger stuff.
http://www2.towerhobbies.com/cgi-bin...?&I=LXA379&P=7