I am considering swapping my two Dell UltraSharp U2713H monitors for six Dell UltraSharp U2414H monitors. The monitors will be in a 2 x 3 layout with the top row rotated 180º so that the ultra slim bezel will be on the inside edges. Currently I have a 5780 video card in my Mac Pro 4,1 flashed to a 5,1. In the other PCIe slots I have a Sonnet Tempo SSD Pro with 2 x Samsung 840 Evo 1TB drives in a RAID0 and a USB 3.0 card. What would be the best video card(s) to drive the six monitors with? I do not want to loose my boot screen.