you should buy or rent a stereo mic and mont it on your camera with a shock mont.
try the SHURE VP88 heres a link
http://www.bhphotovideo.com/c/product/68506-REG/Shure_VP88_VP88_Mic_with.ht...
and here's a link to a show i shot using it
http://www.vbs.tv/video.php?id=494918804