Honestly forget 4K TVs I don't even know why spoffle mentioned it - most of them can only be driven at 30Hz currently from a PC so utterly useless for any real gaming like COD, etc. (even on a casual basis) and the performance hit is much much bigger than 2560x type resolutions (Source: I have an AOC 2868PQU and various 2560x1080-1600 res panels).
The ROG swift looks like a serious contender but its too early really to be making a reccomendation concerning it. From your original post I would probably hazard on looking at good quality 2560x1440 IPS panels as they will be worth it for stuff like WoW and diablo, etc. where the image quality will produce more benefits than the performance. (EDIT: 144Hz panels are nice to have but are going to be of a lesser benefit to you unless you take COD, etc. fairly seriously).