The Olympus 14-35mm f2.0 has no tripod collar and that's why I passed on it. The 35-100mm f2.0 has a nicely balanced rotating tripod collar that works beautifully with a Manfrotto 393 gimbal head (sure, you could use a panning head, but heavy lenses balance so much better with gimbals):BTW how did you secure 14-35 on your rig? Does GH1 need a lens support?
http://www.amazon.com/Manfrotto-393...1?ie=UTF8&s=electronics&qid=1301941010&sr=8-1
For anything too bulky to handhold, I've totally transitioned to rotating lens collar tripod mounts. This allows me to swap in GH1/GF1/G2 A and B cams just like replaceable camera backs. What's even better is I no longer have to painstakingly level the tripod and head for every shot. Simply rotating the lens works well enough to level the camera for most shots.