Build in progress, Advice apprecited

It looks like a very solid build for an EOL chipset. I understand why you are build it since you were given a free MOBO and have current parts...

Check my thread listed in my signature... I did a similar thing when I built my daughter's Dad's PC from spare parts I had prior to my Core i7 build.

I would go with this GPU / PSU Combo http://www.newegg.com/Product/ComboDealDetails.aspx?Ite... and change out the HDD to this http://www.newegg.com/Product/Product.aspx?Item=N82E168...

It really depends on your budget tho, If you can look @ this link http://www.tomshardware.com/forum/261222-31-build-advic... and post back it would help out.

APPROXIMATE PURCHASE DATE: A couple months or near Christmas.

BUDGET RANGE: 600$ U.S. max

SYSTEM USAGE FROM MOST TO LEAST IMPORTANT: Gaming, (things like Crysis, WoW, Soon will be playing Modern Warfare 2) and things like web and music.

PARTS NOT REQUIRED: Speakers, keyboard, mouse, monitor, case, motherboard, CD/DVD drive, and CPU cooler.

PREFERRED WEBSITE(S) FOR PARTS: Please Newegg, they are the people i like the most.

PARTS PREFERENCES: ATI please (the Board is CrossfireX)

OVERCLOCKING: Maybe

SLI OR CROSSFIRE: Yes....later

MONITOR RESOLUTION: 1440 x 900

ADDITIONAL COMMENTS:I want to keep the Core 2 Quad cause I don't need the little boost that the i7 has compared to the Quads. Please foregive me if i missed anything!!!!!

Luckily you posted your monitor resolution because now we can determine that your GPU is definitely overkill for your system. Save some money and go for a 4850.
XFX HD-485X-YDFC Radeon HD 4850 512MB 256-bit GDDR3 PCI Express 2.0 x16 HDCP Ready CrossFire Supported Video Card - Retail
http://www.newegg.com/Product/Product.aspx?Item=N82E168...

Also since you save a bit of money you can go with a 640 Black Drive.
http://www.newegg.com/Product/Product.aspx?Item=N82E168...

Lastly 750W PSU is definitely overkill unless you are running some major hardware so unless you plan on crossfiring in the future I suggest that you should consider:
CORSAIR CMPSU-520HX 520W ATX12V v2.2 and EPS12V 2.91 SLI Certified CrossFire Ready 80 PLUS Certified Modular Active PFC Compatible with Core i7 Power Supply - Retail
http://www.newegg.com/Product/Product.aspx?Item=N82E168...
It's $10 more but its modular so less cables/headaches!
... I should have read you were gonna crossfire/SLI

Check out this HDD:
SAMSUNG Spinpoint F3 HD502HJ 500GB 7200 RPM 16MB Cache SATA 3.0Gb/s 3.5" Internal
http://www.newegg.com/Product/Product.aspx?Item=N82E168...

And since you are Crossfiring, stick with the 750W, maybe have a look at this one:
Antec EA750 750W ATX12V version 2.3 SLI Certified CrossFire Ready 80 PLUS Certified Active PFC
http://www.newegg.com/Product/Product.aspx?Item=N82E168...

You said your rez is (MONITOR RESOLUTION: 1440 x 900) If you keep this monitor THEN yes you can go with a 4850, If you plan to upgrade your rez to say 1920X1080 Then your better off getting a 4890 now so you wont need to replace the GPU after a monitor upgrade.