Get the cheap processor, save your money, and if you ever need more CPU power, use that money you saved to buy a cheaper, faster quad-core (when they exist).
W&C speaks wise words.
Anyway while Quadcore is a good choice if you multitask like a little bitch, you will get lower frame rates.
The Q6600 is like the Incredible Hulk, and can carry 400 tons of weight at a 100 miles per hour, while the E6750 is like Superman (post crisis pussy version) able to carry 200 tons but moving at 130 miles per hour. While that extra strength is nice, most bad guys come in at a 100 tons, and will continue to do so for a while.
The E6750 is for some reason a better overclocker as well.
I can totally agree with Wind on the processor. As for the card, see how much you can get a 7800 or 7900 for. Dx10 features are overrated (and useless if you're not using Vista), and a high end 7 series card should smoke a mid range 8 series card in DX9. I bought a 7900GS for under $100 on sale and am very impressed with the performance for the price.
The 7900GS is a pretty good card, but the 8800GT is just a great choice. It doesn't matter if DX10 is overrated, as the 8800GT is the
best DX9 card as well. In fact there isn't a card out there that can run DX10 effects without taking a noticable performance hit. I've played Company of Heroes, World in Conflict, Crysis etc on both Vista and XP. While I've noticed better effects in the DX10 versions of those games, I've noticed a significant slowdown compared to XP that just wasn't worth the DX10 sexiness.
It may not be a hardware problem, but rather a software issue that can be fixed with SP1. That is my hope anyway.
As for the 8800GT vs the 7900GS: You are going to pay another $130 once, and can insure that you will be able to play just about every game out there on max settigns, and for years to come. All the new tech is now out, including the new Unreal engine as well as the Crytek engine. On XP, the card runs Crysis on high settings fairly well. It runs the Unreal engine on max settings beautifully, which is basically the technology most games are based on these days.
One last thing. Do you plan to upgrade to a monitor with a high resolution later? If so, it is another reason in my opinion to get the 8800GT.
Finally some benchmarks:
http://www.tomshardware.com/2007/12/12/geforce_8800_gts_512_mb/page10.htmlWith the newer drivers, the 8600GT and the 7900GS perform near the same levels. So taking that into account, you will notice the 8800GT getting nearly
three times the performance as the 8600GT.
http://www.anandtech.com/video/showdoc.aspx?i=3140&p=8According to those benchmarks the 7900GS is a good card if you are going to stick to lower resolutions and are not interested in anti aliasing or anisotropic filtering. With those settings the 7900GS does well in games like UT3 getting about 50 fps. In COD4 it gets about 50 fps which is quite good. In Bioshock it gets down to 30 fps, 20 in Oblivion and 15 in Crysis.
On higher resolutions it struggles though, and if you like AF or AA, the card isn't for you. To me the 8800GT is a better future investment.