Here is a Quick Take on the Ultralight Control Systems Arm. This is one of the most stable accessory arms on the market. It has a very sturdy ball mount tie down and various size scaffolding to configure for any on camera situation. The one shown here has a Cardellini Clamp that will let you mount it almost anywhere to almost anything. It can be replaced with a hot shoe mout adapter for camera top use. This would actually cost a little less than the configuration shown. We picked up this one at http://www.filmtools.com for around $200. Dig it.