Upgrading Desktop PC

[Rednog]

So my mom recently asked me to build her a computer, and I figured I might as well use the money to upgrade my own parts and build a pc with the parts I replace/have extra.
So right now I have a
EVGA 123-YW-E175-A1 LGA 775 NVIDIA nForce 750i SLI FTW ATX Intel Motherboard
Intel Core 2 Duo E7300 Wolfdale 2.66GHz LGA 775 Dual-Core Processor BX80571E7300
CORSAIR DOMINATOR 4GB (2 x 2GB) 240-Pin DDR2 SDRAM DDR2 1066 (PC2 8500) Dual Channel Kit Desktop Memory Model TWIN2X4096-8500C5D

I want to replace those for my gaming rig.
I'm looking for advice on what to upgrade on. I have about $400-500 to do it. Aiming a bit towards the $400 since I'm probably going to be buying http://www.newegg.com/Product/Product.aspx?Item=N82E16811146073&cm_mmc=BF2011_listing-_-7-_-N82E16811146073&nm_mc=BF2011_listing
for a tower because my antec 900 has given me terrible headaches in the past when it comes to cramming stuff inside.

I was looking into the new 8 cores from AMD, but my roomate told me that it was pointless to buy an 8 core when the 6 cores are better.

 

[Ziadaine_v1legacy]

....Has that motherboard got ON BOARD Graphics?


You're best replacing everything and I beg you PLEASE dont get either 8 or 6 cores from AMD. they're immensely redundant with todays current hardware (and not as stable as Intel i5 2500k/i7 or something)

 

[Rednog]

....Has that motherboard got ON BOARD Graphics?


You're best replacing everything and I beg you PLEASE dont get either 8 or 6 cores from AMD. they're immensely redundant with todays current hardware (and not as stable as Intel i5 2500k/i7 or something)

I have a HD Radeon 6950, I'm just saying out of the parts I currently have those are the ones that are still from my original build.
Links to what you recommend would be highly appreciated.

 

[number2301]

I haven't got links but get a Z68 motherboard and an i5 2500k. Don't touch the new AMD FX chips, they're rubbish.

 

[RhombusHatesYou]

I haven't got links but get a Z68 motherboard and an i5 2500k.

And a good aftermarket HSF. Might as well just buy the 2500 if you're not going to OC the tits off a 2500k.

Hell, if the budget stretches far enough a high end closed loop water cooling system (Hydro, Kuhler, those sorts of units) and really go nuts OCing the CPU.