Homebuild System help/recommendations (OC'd 805D/Core Duo?)

Hello,

I am tentatively planning on putting the following together:

case
GIGABYTE 3D AURORA GZ-FSCA1-ATB ATX Full Tower
power
HIPER HPU-4K580-MS ATX12V 580W
HD
Seagate Barracuda 7200.10 320GB 7200 RPM 16MB Cache SATA 3.0Gb/s
mem
CORSAIR XMS2 2GB (2 x 1GB) 240-Pin DDR2 SDRAM DDR2 675 (PC2 5400) - already purchased
Vid
GIGABYTE GV-NX76T256D-RH GeForce 7600GT 256MB 128-bit GDDR3 PCI e16 - already purchased
CD - recycled DVD/CDR drives
Sound - onboard sound - if it's reasonably decent
cooling
Zalman CNPS7000A-Cu recycled - with adapter for lga775

mobo
ASUS P5ND2-SLI Socket T (LGA 775) NVIDIA nForce 4 SLI Intel Edition ATX
processor
Pentium D 805 Smithfield - overclocked to 3.6 - air cooled?


My primary motivation is so I can play Oblivion and other high end games. Other than that, websurfing but possibly for media related things, like setting up a 'Tivo' box and burning DVDs.

I'd like the system to be as quiet as possible without watercooling with another PCI slot or more.


I'll be running Windows XP Home, and probably won't upgrade to Vista for at least several months after release.

My concerns:
The vid card is a silent pipe II and the mobo north/south bridges are not actively cooled. I was hoping the Aurora case had enough good air flow that it wouldn't be an issue, but everyone says the Northbridge runs very hot on the motherboard and I didn't know if overclocking the 805D would exacerbate this.

My dilemma/options:
1) system as listed above - if there aren't any issues with it.

2) Intel 805D with a different mobo that would allow overclocking, but be "forward compatible" if I upgrade to a CD2 processor - and maybe Windows Vista - next year. Any motherboard reccomendations, under/around $150ish?

3) as above, except with a different mobo and a CD2 processor now. I basically put the system above together a few months ago. The motherboard and 805D will run me about $200, and I plan on overclocking it. However, if I can get a good mobo and CD2 for $400ish - that would be significantly better than OCing the 805D - I'd likely do that. Recommendations?

I'm leaning towards option #2, but haven't researched any motherboards lately. I'm somewhat flexible on component prices and don't mind spending a bit more but I'm talking $20 here, $50 there. Not $400+ for a processor or anything like that. Basically, I tried to stick to an average of $100-$150 for all the base components - except the 2G of ram.

If anyone, 'altruists' or others, could give me some thoughts I'd greatly appreciate it. I've not done much research on the Core Duo processors so I don't know how they compare to an over-clocked 805D, value wise.

Thanks,

JJAG

I couldnt find any head-to-head reviews of the OC'd 805D and any C2D. But if you check the THG Article 805D OC'd to 4.1Ghz you'll see that the 805D OC'd peformed very similar to the P4 EE 3.73Ghz Prescott.
And you can use the THG CPU chart to compare the stock CD2's with the P4 EE 3.73Ghz. It looked to me that the E6400 held around 20-30% advantage at stock speed.
THG CPU Chart P4 EE 3.73 Prescott vs C2D E6400