Well there is a RoG 4K PG27AQ coming out soon.

This monitor: Acer Predator XR341CK 34" should be released shortly. The FreeSync edition is already out. ASUS is also coming out with something similar. I will wait till I get a monitor for my build.

The current rog swift is the best performing and bang for the buck. I just finished putting my 980ti sli system together, wow. Running BF4 at 1440p, 90 fov, ultra almost everything, 150 res scale up and getting 140-160fps... My triple 780ti kingpin wc setup gets close to this but not quite...

People wait ASUS 3800R... I read hysteria for Swift and other ASUS monitors and I agree they are offer excellent performance, nice and cool but everything finish on that. Same what we had before 5-6-7 years only little better performance collect on one place. 
ASUS 3800R is something completely new, I never had wish to buy ASUS Swift or some other their 4K monitor, OK I agree on papers maybe they are best, but market need something new, monitor of next generation.... Same as I say for Obsidian 650D in 2011 I must to have that case, or other components, graphic cards, same is for this monitor...Special back side of him...I usually don't like such futuristic stuff because designers usually made from them childish stuff, but this is futuristic on best possible way...OK maybe they should done little nicer legs from front side...but that's only little thing... flaw is it's not 4K...
but anyway I could afford only up to 2560x1440p gaming.... Thanks to NVIDIA drivers and now many old games I play and on 2560x1440p on 1080p monitor.
And I have no problem from 60 fps... better 60fps on 2560x1440p than 120 fps on 1080p... for 120fps on 2560x1440p you need at least two TITAN X in SLI and disabled AA. 
 

 I look on him as 2560x1550p monitor...
He is bigger and than it's better because resolution is bigger but price should be below 4K monitors.
 
 

HOT POCKET
Thanks for the input I was able to pick up a ASUS swift for $700

For $100 more ($799) you could've gotten the 144hz IPS Acer XB270HU w/ gsync. A TN monitor is just not worth $700 today in my opinion, considering the Acer monitor out now and the soon to be released Asus 144hz IPS. I returned a 1080p 144hz one because I got sick of the top of the screen looking different from the bottom even when looking at it dead on while just browsing or doing actual work aside from gaming. But I get that $100 difference is a lot of money. So enjoy the monitor and 144hz greatness.

$1400 budget on SLI cards with a $400 budget on a monitor does not make sense to me lol.
You could get a used beat up ROG swift with dead pixels and BLB for around 550? Maybe?
 
Save and invest in 1440p monitors. 3440x1440p predator will only be 75hz. The 2560x1080 will be 144hz. Then there's 4k monitors. Prepare to play the silicon lottery no matter what company you buy from. The 3340x1440p would IMO be the best choice but you are limited to 60hz like me or 75 hz if you get the new predator 1440p. 2560x1080p is a step backwards to me..
 
2560x1440 at 144hz is great but again you will be paying around 800 for a 27 inch screen which is plain crazy to me, but to each his own. 
 
I have the LG 3440x1440p lg34um95P. It took 8 returns to get a decent one. I have 1 Samsung 4k 50 inch that is perfect luckily on the first one..
 
The only viable option in your budget is the QNIX 2710 or overlord types of A- Korean panels that MAY or MAY not overclock to 120hz. I understand that most are using PWM now so you may need to research. I had one that would do 110 but I eventually sold it because 27 is just too small for me and always gravitated back to 21:9 3440x1440p or 16:9 4k. 
 
Try blurbusters.net

I had a chance to look at and mess around with the Acer XB280HK 4k G-Sync monitor also. They didn't have a Acer XB270HU in-stock at my local Micro Center so no go on that one. I like to see the product in person before buying it. I'm not going to lie that I'm not a fan of Acer from past purchases and bad product. I know they have improved from the past but I'm still sour about it. Not saying Asus is better either. If Samsung made a IPS 120Hz 1440P monitor I would be all over it.