In the market of a new graphics card

Solution
A 1080 ti will compliment your build well, its a good match for 1440p 144hz but again its not cheap. A 1080 will also do very well at that resolution, its about 20-30% slower than the 1080 ti depending on the game.
600 dollars is WAY too expensive for a 1080, whether or not it has a water cooler. You can get 1080s for around $400.

The 1080 ti is the more powerful card, but very expensive and you need a high end monitor to take full advantage of it. What cpu do you plan on using? And what is the refresh rate and resolution of your monitor?
 
Oh i know i was not going to buy it at that price. The cpu is the intel i7 6600k skylake and my monitor refresh rate is 144hz and the resolution is 2560x1440