GTX680 MSI Lightning edition and 1440p IPS screen

Renzkuken1

Honorable
Aug 4, 2012
103
0
10,680
Hey guys, i build my rig more than a year ago and am getting the itch to upgrade.
This is my current build:

i5 3570k OC at 4.7ghz
850w psu
gtx680 msi lightning overclocked to 1400mhz
asus sabertooth mobo
8gb ram
korean ips 2560x1440p 27" monitor

So my questions i have are...should i sli my gtx 680 to get better fps at 1440p resolutions and have more chance at running better fps on 2560x1600 and if you think i should SLI what cards are compatible to sli with the gtx 680 (As i purchased my current msi lightning for $650 and the cheapest i have seen is $700....go figure...)

Or should i purchase a 27" benq 1080p 144hz screen and leave gpu as single 680...(State whether you can see a difference in 60hz and 144hz..) or should i get a 1440p screen that can overclock to 120hz?

I'm really not sure what road to take here...atm i get a GPU score of 12000 on 3dmark11 and a heaven score of 97.

Thanks for all the input.

Chris.