Advice on Quad-Core Gaming Machine: Kentsfield or Yorkfield?

Hello All,
Need some advice on what CPU to buy. I'm planning to build a gaming system that I hope will last several years. I need to keep the CPU cost around $250. I've narrowed it down to these choices:

Intel Core 2 Quad Q6600 Kentsfield; 2.40GHz 2 x 4MB L2 Cache; 65nm; 1066MHz ($189.99)
Intel Core 2 Quad Q8200 Yorkfield; 2.33GHz 4MB L2 Cache; 45nm; 1333MHz ($224.99)
Intel Core 2 Quad Q9300 Yorkfield; 2.50GHz 6MB L2 Cache; 45nm; 1333MHz ($259.99)
Intel Core 2 Quad Q9400 Yorkfield; 2.66GHz 6MB L2 Cache; 45nm; 1333MHz ($269.99)

I'm leaning towards the Q9300 but am attracted to the Q6600 price point. Then of course, the Q8200 is right in the middle. Which one would you recommend and why? I'm planning to overclock, but this will be my first time overclocking so the results will be modest at best. Here are the rest of the system specs:

ASUS P5Q Deluxe LGA 775
VisionTek 900244 Radeon HD 4870
PC Power & Cooling S75QB 750W ATX12V
mushkin 4GB (2 x 2GB) 240-Pin DDR2 SDRAM DDR2 800
XIGMATEK HDT-S1283 120mm Rifle CPU Cooler


Thanks in advance for the help.


PS - Please make suggestions on the rest of the components if need be. Thanks!

^agreed. The Q6600 is by far the best price for performance, especially when overclocked

Q6700 is not necessary, it's same as q6600, but with 10x instead of 9x multiplier. Current chipsets like x38/48/p45 runs at 1600(4x400)mhz fsb natively, without overclocking. 9x400=3.6ghz, which should be enough for most people.

Q6600 cost $185 right now.
http://www.newegg.com/Product/Prod [...] 6819115018
Paying $251.84 for the 10x multiplier is just not worth it.

You could save a lot of money by going for the ATI Radeon HD 4850 graphics card instead like this one.
http://www.newegg.com/Product/Prod [...] 6814102770

It would be fairly inexpensive to run 2 of these in crossfire and after the rebate would come to less than $300 for 2 of these cards.

Thanks, everyone. I'm going with the Q6600.

Cheers.