Even a second 980 won't really get you a 2560x1440 at 144Hz on more graphically intensive games. Personally I would get the 3440x1440 or a good 2560x1440 or a good 120Hz 1920x1080.
LG 34UM95 for the 3440x1440
BenQ GW2765HT for the 2560x1440
Eizo FG2421 for the 120Hz 1920x1080
A normal 1920x1080 would be Eizo EV2450. Very good monitor but it's 1920x1080 of course.
Personally I'd go with a 4790k but that's just me.