just an idea, if you don't want to build one yourself, you could always buy a yogsblast or something (note: I am not exprinced in this subjext, please don't hate on me id it's overpriced or something)

I would recommend building one yourself, you get to choose custom parts and it is often cheaper than a prebuilt.

I would suggest building your own computer if you can figure it out, it's hard, but it's cheaper, better and faster. If you do buy a pre-built on, DO NOT buy alienware, it's good, but it's god-darn over-priced.

You have a good amount of money to build a nice and fast computer, I wouldn't be able to guarantee anything about Battlefield 4 we all have to wait for the minimum specs to be released by Dice.

If you have previous knowledge of building a computer yourself then do that it will save you a little bit of money if not look around for some websites. When i was looking at computer parts etc i took at look at this site: http://www.cyberpowersystem.com/

If you want to overclocking you have to be careful with what you are doing and how much you overclock you're computer. I wouldn't advise Overclocking straight away since it can damage you're computer internally.

You're best bet would to be focusing on the graphics card and spending more money on that, For example getting the i7-3770 Approx 3.5Ghz Clock speed is pretty much enough for most games out now, with the graphics card you are wanting to spend a little bit more money so i would look at the Nvidia GTX 660, Nvidia GTX 660Ti. They are 2 good graphics cards and will run you're games at good performance.

Whilst making or customizing you're computer make sure your power supply is high enough to support everything in you're computer. 750W would be more than enough for the basic things your processor, graphics card and any future upgrades you would be making.