Gtx 1060 6gb for 1440p?

Solution
GTX1060 is about on par with GTX970.
It is only a budget solution for 1440p.
It is better to go for GTX1070 at very least.
BTW, wait for the coming AMD's GPUs, if you can.
Depends on the game and monitor. I have a 1440p gsync screen with a 1060 6gb and it does better than you expect in some titles but settings have to be turned down on others. If you use v sync and need to output at least 60fps then you will be playing games on medium. If you have gsync you get away with the frame rate dipping below 60 occasionally.