Hmmm...
This is my thread with my screen
http://forum.1cpublishing.eu/showthread.php?t=23199
3072x1024 CoD in WINDOW mode (and my desktop is 3840x1024)
Why do you say you need to run SLI ???? I can also run the same resolution using only one card.
I have connected my monitors using Matrox's TrippleHead2Go, probably this makes the difference but I think you should check.
Especialy because your GTX590 should be able to use all 3Gb with one ccore and this should give you excellent performance.
~S~