I'm sure I saw somewhere someone selling wireless helmet cams. When I say wireless, I mean no nasty cables and battery packs - just a lipstick cam and a reciever to go on the camcorder. Google can't help, so am I dreaming?
you can get a unit that uses a memory stick type recording pack its in this months MBR light and frill free
you should be able to use any standard CCD with decoder camera (ie it will plug streight into a scart) as long as your camcorder has an AUX in and you have some way of powering the camera module some thing like this modded with a helmet light bracket might suffice IP67= very water and dirt proof