http://www.overclock.net/t/1549176/official-acer-predator-xb270hu-owners-club

So I recently purchased the Acer Predator XB270HU. This is the single most expensive component I've purchased in my life, and with good reason.

This monitor's features that were attractive to me were the 1440p (2K) resolution, 144Hz, Gsync and IPS panel.

What I'd like to know is what is the best graphics card to go with this monitor. I think it is basically impossible for any single card to actually fully max out this monitor on contemporary games. On Counterstrike and TF2 this monitor is a joy to play on, getting the full 144fps to take advantage of my monitor while running at the 2560x1440 resolution thanks to my GTX 970. Though games like Witcher 3, Arkham Knight, Mad Max, etc, it is a struggle to run even 60fps at 1440p.

Should I get a second 970 for SLI or a 980 TI for 1440p gaming? I have a friend who is willing to buy the 970 at nearly full cost, so that's the question I'm wrestling with atm.

Thanks.