There are a few good sd cameras by sony and panasonic now. just look for somthing with 3ccd, cause some of these new hd sd card cameras don't have a 3ccd chip, and i've read that they give jerky vision. The trackvision forums have some good info on cameras.
http://trackvision.net/phpBB2/viewforum.php?f=10
we used a go pro in targa. video is alright, sound is not much. i've currently got it pulled apart beside me, i'm going to move/change the mic, and put some wind protection on it. And move the start and stop button so we get every stage this year.