[slatton86]

An idea for a solution on multiple channels and one PC would be a bit tedious to set up but here we go, I'll base it on 3 channels

3 PCI video cards with S/composite out, or more if you have the slots.
3 cheap USB sound cards
Use built in/AGP/PCIE what ever you have and your built in sound for your monitor to make this a little easier.

build, setup, install drivers,
Windows should give you 3 desktops now.
Open VLC 3 times drag each one to a different desktop.
Go to each one and manually select the audio output device and fullscreen it after setting up the playlist.

Personally I would stack 3 original XBOX'x loaded with XBMC for simplicity, but hey you work with what you got, at least I do.