imajim :
RobCrezz :
A crappy GT 610 can do that resolution and two screens.
So is GT 610 above my current GTX 275? Was told to get GTX-680 w/4GB
Just to drive two monitors, you don't need hardly anything. Your GTX 275 is already fine if its got the monitor outputs you need. As RobCrezz said, a cheap-ish mid-range card would be plenty if you want access to CUDA acceleration, too.
You need nothing even remotely as expensive as a GTX 680 unless you were going to game at 2560x1440, and you said you weren't.
Photoshop performance relies a lot more on having enough RAM and a fast scratch disk. An SSD would be a good investment if you haven't already got one.