First time builder! Gaming PC 700~800$ish

*EDIT* Waiting a bit longer suggested by dirtmountain. Will bump the topic up later when I am ready!


APPROXIMATE PURCHASE DATE: Withing a week or two
BUDGET RANGE: US$700-800ish
SYSTEM USAGE FROM MOST TO LEAST IMPORTANT: Gaming
PARTS NOT REQUIRED: Keyboard, Mouse, Monitor, Speakers
PREFERRED WEBSITE(S) FOR PARTS: newegg.com
PARTS PREFERENCES: I'd prefer an Intel CPU
OVERCLOCKING: Maybe in a few years not right now
SLI OR CROSSFIRE: Maybe in a few years, but most likely not
MONITOR RESOLUTION: (1680 x 1050)

My current computer is a 6+ year old Sony Vaio and I need a new computer to keep up with the new and upcoming games! I'm a little scared to build the computer but I read a lot of tutorials and saw various videos on youtube, that combined with the manuals that will come with the parts I feel like I should beable to do it!

CPU: Intel Core 2 Quad Q9550 http://www.newegg.com/Product/Product.aspx?Item=N82E168...
RAM: Crucial 4GB DDR3 1333 http://www.newegg.com/Product/Product.aspx?Item=N82E168...
MOBO: ?
GPU: XFX Radeon HD 1GB 256bit http://www.newegg.com/Product/Product.aspx?Item=N82E168...
PSU: Corsair 650W http://www.newegg.com/Product/Product.aspx?Item=N82E168...
HDD: Western Digital 640GB http://www.newegg.com/Product/Product.aspx?Item=N82E168...
CD: LG 22x http://www.newegg.com/Product/Product.aspx?Item=N82E168...
CASE: NZXT Guardian http://www.newegg.com/Product/Product.aspx?Item=N82E168...
or perhaps the popular Antec 900 http://www.newegg.com/Product/Product.aspx?Item=N82E168...

Total @ newegg with all the parts added in separately (no combos)
~$685.93 with $45.00 with rebates. Microcenter has the CPU for $50 Cheaper as well
(I used the NZXT Guardian for the case)

I appreciate all the help and tweaking that I will get from you more experienced builders :]