I want to install a second video card that is bridged to the existing NVIDA GenForce 7300 GT in a manner that all 4 displays work in sync together like they currently do with the 2 I have installed. I am currently running 2-24" Samsung Displays at 1920X1200. I have been told that I must use another identical NVIDA card and it must be the OEM version, not the Retail versions. My mac pro version is designated 1,1 and I'm running 10.5.2. I'd really like to boost the 2nd Card to one w/ more features memory. Any suggestions?