Erm, I believe your terminology may be slightly wrong, there's no such thing as a "Composite" audio Cable, there are "Compositing" USB devices which can composite a Composite Video signal and a Line in from an RCA cable, however :P
The name composite is given to composite video because the colour and black and white values are composited into a single signal.
Perhaps you are looking for a device with the wrong name?
It's not about what camera you use or how much it cost.
It's about what you shoot,
how you shot it,
and how you edit it :P