If you want to go 27 inch for gaming there are only a few monitors that has very low input lag and high refresh rates
Asus VG278HR
BenQ XL2720Z
The 27 inch Asus has GamePlus (OnScreen Overlayed Crosshair/Timer) features that is the same as Asus VG248QE
If you can wait for a period of time
the
Asus SWIFT PQ278Q might be a good choice. It is the first monitor to officially included G-Sync