Trying to buy a new computer..

[Tokochan]

Since I have absolutely no clue what I am doing I figured I'd ask here for help XD

I'm trying to get a new computer as well as looked into making my own. Problem is even though I've looked a videos and read articles on building a gaming computer I still am at a loss.. After weighing my options I have decided to just buy a prebuilt computer although I won't get as much as I want for the money it'll just be a lot easier for me >_o
Anyway.. I have a budget from around $600-$700 and I did find two computers on Newegg that I think I like.. But I just don't know what I should be looking at :/
If anyone could give me advice that'd be great ^_^;

These are the two I saw on Newegg:
http://www.newegg.com/Product/Produc...82E16883258020

http://www.newegg.com/Product/Produc...82E16883229438

EDIT: Gonna write here because I reached my reply limit apperently >_>
I used that cyberpowerpc site to customize something.. (Thank you bidred) so here's that
http://www.cyberpowerpc.com/saved/1FM8DD
The Nvidia graphics card gave a boost in fps.. also was $2 cheaper XD and a friend of mine is more familiar with them so thats why I picked that one.. otherwise I'm not really sure what I should pick x.x;;;
and if the link doesn't work..
CPU: AMD FX-6300 3.50 GHz Six-Core AM3+ CPU 6MB L2 Cache & Turbo Core Technology
HDD: 1TB SATA-III 6.0Gb/s 32MB Cache 7200RPM HDD (Single Drive)
MEMORY: 8GB (4GBx2) DDR3/1866MHz Dual Channel Memory [+37] (ADATA XPG V2)
MOTHERBOARD: GIGABYTE 970A-DS3P AMD 970 ATX w/ Ultra Durable 4 Classic, On/Off Charge, GbLAN, 2 PCIe x16, 3 PCIe x1, 2 PCI
SOUND: HIGH DEFINITION ON-BOARD 7.1 AUDIO
VIDEO: NVIDIA GeForce GT 640 2GB GDDR3 PCIe 3.0 x16 Video Card [-2] (Major Brand Powered by NVIDIA)


NEW EDIT:
Thank you everyone for the help ^_^ you've all convinced me to look for parts and built it myself XD
Only questions I have now are which parts are the best for the money.. but a couple of the sites you guys posted already have that so thank you i'll have to really look them over~