You need to take this step by step. The importance for a gaming machine is as follows:
Monitor
GPU
CPU
Motherboard
Memory/Storage
Power Supply
As of now the sweet spot for monitors is 1920X1080. Good prices.
Also consider a 1920X1200, the extra height is really nice. I have one at home. Great for many things, but at greater cost.
Then you have your 2560X1440 and even 2560X1600's. Great monitors that will really add to your gaming experience, but will drain your wallet too. Also, to get some decent rates you will need a 690 or 7990 or SLI/CF graphics cards.
Finally, you have triple monitors. This puts you at the bleeding edge of graphics goodness and hardware demand.
For graphics, to absolutely kill any game you need about a 690/680SLIX2 or 7990/7970CFX2 for a 1920X1080 or 1200 display. For the 2560X1440 or 1600, you will need triple SLI/CF or, better, SLIX2 Titan. For triple displays, you will need three Titans and good bank robbing skills.
Of course, this is for games like Far Cry 3, Crisis 3, and Metro 2033. The toughest games at the highest levels.
2GB video ram is enough for up to 1920X1200, 3GB is enough for 2560X1600, 4GB for triple displays.
The word is the I5-3570K is the best value for gaming. I think the AMD 8350 is okay too, once you download some hotfixes to optimize Windows for AMD.
Be sure to get an aftermarket cooler for the processor, Cooler Master 212 EVO is the present performance2price winner.
Motherboards, there are way too many choices. Just make sure it is a Z77 board for Intel, I'm not sure what the equivalent is for AMD.
8GB ram is good, 16GB is some cheap overkill for the future. I'd get 1600 MHz speed and NO heat spreaders so it will fit cleanly under the CPU cooler. With Intel, anything faster than 1600MHz doesn't help since the memory management and cache system is so good. Faster RAM is expensive and helps AMD.
SSD are a nice luxury. Get at least 120GB, 240GB if you can, and put everything on it. Just have a HDD of 0.5TB or larger for music & videos/music and games not active.
PS, make sure it is a quality one with a good 20% or more capacity beyond what is needed. Use PCPARTPICKER.COM to enter your build and see what the power required is. I'd go for a gold or platinum rated one and semi/fully modular to decrease case clutter of unused cables.