Mobo/CPU Question for a Friend

You guys have always been helpful so I thought I'd give my roommate a [H]ard answer on what he should get for his PC rather than speaking from experience, considering I've been stuck with AMD for 3 years now.

He plays mostly WoW and CS:S on his computer with the occasional CoD 5. He's already got a gtx 260 core 216 on the way but his processor is older than mine (2.8 ghz p4) and it can't handle anything anymore. I thought my PC was bottlenecked a lot but without a new mobo/cpu he may be in for quite the surprise :X.

He's looking for a socket 775 mobo + cpu that would help him out the most. He folds for our campus team and doesn't have more than $350 to spend at the moment. I'm just kind of stuck on whether he should go dual or quad-core, and I'm not sure because I don't know how many cores any of those games pick up and at the moment he doesn't do anything more performance intensive than CoD5.

I'd appreciate any feedback. I'm guessing people will say Q6600 because in the future games will utilize more cores, but this is probably only going to be used by him for another year and a half until we graduate.

Three combo deals:

$270 - Intel Core 2 Duo E8400 & Gigabyte GA-EP45-UD3R combo

$285 - Intel Core 2 Duo E8400 & Gigabyte GA-EP45-UD3P combo

$310 - Intel Core 2 Quad Q6600 & Gigabyte GA-EP45-UD3P combo

Likewise, your friend could pair up either the E8400 or the Q6600 with the Gigabyte GA-EP43-DS3L motherboard... if he doesn't need that many features with the board.

The additional cores on the Q6600 can help with folding, but they're not a necessity if folding isn't the primary use of this machine.

Thanks much tiraides. He has a buttload of case fans and really doesnt have any leftover spots on his mobo which has 5 i believe. I guess that's the only thing that might hold him back, but that mobo def. looks good.