Mac Pro :: Mixing VGA And DVI Monitors With 5770?

I've seen the Apple articles and the forum posts about this, but before I need to check my configuration will work before it has to be used on a show at work (the MP is running screens in a venue). I've seen lots of scenarios with people using all DVI monitors or all VGA, but can't find any examples where they are mixed. 

Here is my proposed setup: 

DVI output - 800 x 600 - First device (DVI input only)

Mini Display Port 1 - also 800 x 600 - Second device (DVI/VGA input but strongly prefer to use DVI) via Mini Display Port -> DVI adapter (passive?)Mini Display Port 2 - 1376 x 7?? - Monitor running the UI (VGA input) via Mini Display Port -> VGA adapter (active?) My worry is that there is only one active adapter in the system? If this won't work, I have two backup plans, which I would also like to know if it will work or not, please. One of the DVI devices has a buffered DVI link out, so I could use that to feed the other DVI device. So Backup plan 1: DVI output - 800 x 600 - DVI in of first device Mini Display Port 1 - 1376 x 7?? - Monitor running the UI (VGA input) via Mini Display Port -> VGA adapter (active?) MDP 2 not used. 

Backup plan 2: 

DVI output - 800 x 600 - DVI in of first device

Mini Display Port 1 - also 800 x 600 - Second device, VGA input via Mini Display Port -> VGA adapter

Mini Display Port 2 - 1376 x 7?? - Monitor running the UI (VGA input) via Mini Display Port -> VGA adapter 

Info:
Mac Pro, Mac OS X (10.7.4)