Monitor choosing Help?

[Yunanimity]

Hey Guys,
So I am planning to buy a monitor for Gaming, as I am only using a 720p monitor currently running at 60hz. So when I was looking for some, I came across 2 types that I wanted, but couldn't choose between; 144 hz 1080p or 1440p 60hz 2:9 ultrawide. My budget being £400 (642.41USD) can you help me choose and If you can tell me which type of monitor to go for, what make and model I should get?
Thanks guys.

 

[TechCIDLC]

ASUS PB278QE.

 

[fkr]

i have a 2560x1440 monitor that is overclocked to 110hz and i love the color richness and the resolution is something i can never go back down from. it is not as responsive as my older 1080p monitor which many people do not like for the FPS games and such. I play allot of RPG's and strategy games so it does not really bother me as much.

you are going to want to have at least a gtx970 or r9 290 to play on these monitors and 3 gig video card is a must. I am currently thinking about moving up to a four gig card for some of the modded games i play