Myself and a few others have 'DIY'd it for cheap, using the head from a tripod and an exhaust clamp or two round the bar, solid as a rock, its worked fine on all the trackdays ive done!
this isnt any good is it buddy
http://www.maplin.co.uk/Module.aspx?ModuleNo=45385
maplin have stores as well as mail order
Got any pics of said DIY rig ?
What about a Gorillapod? Wrap it round the cage?