Thanks Bob,
I did check with Marc, and he wasn't aware of anybody that had done it, and recommended I pose the question in this venue - I think Matt used his to drive the VP-200 - but I'll have the VPX.
I think the 5600 has 3 inputs per screen as well, so that might be the limiting factor for me as well, although I think I could make it by with 6 total - will have to do some more thinking...
thanks!
Phil