Actually, since I have now read and re-read your post several times, it occurs to me you may be trying to describe the kind of camera support systems made by Steadicam and other companies.
When they are designed for professional use, these types of camera support systems can be quite expensive and cumbersome. If you are just starting out as a cinematographer, you may find it more expedient to use a small, light-weight camera, and practice holding it steady to achieve the shots you want.
A small monopod can also be extremely helpful in stabilizing a light-weight camera, and is an inexpensive solution for steady filming. A good monopod for a small camera will be one that weighs enough to provide a counter-weight to the camera, so that the balance point lies just below where the camera attaches to monopod. This counter-weight will allow you to "fly" the camera through the air with your arm, avoiding much of the vibration, pitching and rolling movements normally found with hand-held videography. Another good trick is to use an elastic camera strap in conjunction with a monopod to further stabilize the camera.
Tiffen makes a product called the Steady Stick that some people have found quite handy.
Edited Sat 13 Feb 2010
by James Longley