Thanks everyone for your help and insight.
I believe we’re going to go with DT Video Labs and Playback Pro. I emailed them really late one night, and they were johnny-on-the-spot, getting back to me within the hour.
Their representative stated that through “discreet output channels” within QT settings, that Playback Pro can manage multi-channel playback with the video. So this is great! His example of such is the massive amount of multi-audio channelling that the Blue Man Group stage productions employ with their product.
So there’s my answer. That, with an M-Audio ProFire 610 to physically split the audio, and all in all, my client and I are spending less than $6000 for all of the hardware for the production. This makes the two of us very happy.
When we’re out there gigging, I’ll make sure to post some some pictures or video for this thread to see the end result of your advice.
Thanks again!
“We are what we repeatedly do. Excellence then, is not an act, but a habit.” – Aristotle