The website Cameratown has compiled a list of follow focus units for use with HDSLR cameras such as the Panasonic GH1, Canon D5, Canon D7 and Nikon D90. I used a follow focus unit on Rejouer, but none of the models listed here. A good set of quality lenses, an experienced AC and a good follow focus unit will add greatly to the look of your movie. Lots of people focus on the camera's sensor, but the lenses, knowing how to use them and having the right support tools is crucial to getting that movie quality that can't be replicated as easily with still lenses.

http://www.cameratown.com/articles/dslr_cinematography2.cfm