The Race Cam comes with a mono-ball swivel mounted on a short bar with an indent and holes so you can tie-wrap it to your roll cage or whatever.
I want to see more of the track than the cockpit so I have the remote head mounted as close to the front windshield as possible and I get a great view looking over the hood out on the track.
Most times I use the passenger seat belt to secure the foam lined bag holding the camera. (I have a 5-point system but you can adapt something to the bag to work with a lap belt only)
To make use of the high resolution system, your camcorder must have an S-video input, audio/video stereo input, as well as a Lanc input to remotely switch the power and record features of the camera. I've used a Sony DCR - TRV900, which is now an older digital model, and I recently have been using a DCR - TRV18 which is smaller but still has all the features and connections.
Race Cam's standard resolution product is a little cheaper - $950, but I would call them and ask advice concerning compatability and picture quality - I haven't used that setup.