Most dj;s connect their setup (mixer+turntables/Controller+traktor/Mixer+cd players) to the computer: Mixer out-->> Line in from the soundcard.
Any cam that works can do the job, Logitech has some good cheap ones.
We use an encoder to encode the music from the computer to the radio. Video is streamed using
www.livestream.com
You can choose any cable you like, except those that are broken
Hope this helps