mikeyyve

I would make sure you are running the latest Nvidia drivers and also that you download something like EVGA Precision X that monitors GPU clock speeds so that you can check and make sure that BF4 is triggering the GPU to increase its clock speed to at least somewhere around 1000mhz.

I would definitely go with that Asus IPS monitor. My brother has that one and the image quality is beyond fantastic and unless you are a pro level gamer I don't believe that extremely high refresh rate and the monitor's response rate are to important.

I was only going 27 inch to get 1440p. More pixels = better quality images IMO

I have a Quickfire TK with red switches and my brother has the one with blue switches. Easily the best keyboards we've ever owned and at a pretty reasonable price all things considered.

You say you have a slow internet connection, yet you didn't tell us what your broadband speed is. It may simply be slow because you have too many devices connected to the internet at the same time and your internet speed is just used at its maximum. You would have to upgrade your LAN equipment only if you were experiencing slow speeds on your LAN. Might just be time for a plan upgrade, not a modem/router/access point upgrade.
 
EDIT : grammar

Check out the CM Storm Quickfire TK. I think it does come in brown switches and also has a backlight as well. I have the version with red switches and love it.

There's a program called Actual Multiple Monitors that has an option called ignore mouse deactivation(or something similar to that) that allows you to be in normal full screen and click on your second screen without causing the game to minimize. 
 
Here's the link to it. http://www.actualtools.com/multiplemonitors/