Have a z75pro3 motherboard currently running 3 monitors with NVIDIA GTX 670 graphics card. Want 5 monitors in surround so would need 2 NVIDIA cards with SLI bridge but SLI not supported by this motherboard- so contemplating switch to AMD . I think I need 2 AMD cards with crossfire -is that correct (to run 5 monitors- eyefinity)? what model card would be best? (Computer will be mainly running a flight sim program -xplane- rendering settings are controllable but want to have them turned up as high as possible which puts big demands on computer)