[Displays] Which monitor for guild wars 2??

Hey everyone,

So i have been researching for hours what monitor to get for my new gaming rig.
I mainly play mmo's so i want to have playing guild wars 2 in mind when giving me opinions.

Is 120hz going to really give me better gameplay for my mmo?

The 3 screens i have been looking at all in the 500 dollar mark and i just want to know which one to get...

The screens are:

BenQ XL2420T (24" 120hz)
Samsung S27A750 (27" 120hz)
Dell U2711 (27" with resolutions 2650 x 1440P)

Or am i better off getting one of the south korean monitors on eBay that have the higher resolutions in 27" or 30"??? If so does anyone know a good buyer to get one off where i won't get dead pixels.

So i guess what my main question is.......Is a 120hz or 2650 x 1440p resolution better for mmo's?

I have a zotac overclocked gtx 670 that will be driving the screen.

Any help would be fantastic! Thanks in advance.