I would go with the 640GB Western Digital HD since I've heard and read a lot of good recommendations with it. And are you planning to go dual SLI now or some time in the future? If not, a 1000W power supply might be a little overkill for your needs and you can save a few bucks there.
If you are looking to keep your cost down, I'd probably stick with the 260, or just start looking toward ATi cards as they are generally cheaper than nVidia and offer good performance.
Go with one of the newer 55nm GTX 260 Core 216s, which you can then overclock to GTX 280 levels.
Use a 750W PSU if you don't want to add a second video card, 850W if you want to leave room to SLI later. Try Corsair TX series, which has models in both of those wattages.
You're missing the operating system, Thermalright LGA 1366 Bolt Thru Kit (backplate for heatsink) and Arctic Cooling MX-2 thermal paste.
If you're only going to have one hard drive, suggest you get the Western Digital Caviar Black 1TB, or 640GB version if you want to save a little money (the 1TB is the faster of the two because of its higher platter density). Spinpoint F1 is good too, but again, suggest 1TB or 640GB.
Any particular reason you want to go with the WS mobo? I like the space between the video cards if you SLI--better cooling.
The i7 will really shine in the future when more applications become quad core optimized. What you are really doing here is building a platform for the future because you can afford the incremental cost over the LGA775. By way of relative comparison, keep in mind that an E8400 easily overclocks above 3.6 GHz. Therefore, on a single threaded application, you're probably not going too much faster.
What I specified from Thermalright was only the backplate, which you will need to mount the heatsink because it is heavy. You could also look at the Thermalright Ultra 120 Extreme 1366RT heatsink itself which is comparable in price, and either one would be fine for your purposes.
I was just musing about your choice of the WS mobo because it was just a little different. I think you misunderstood my comment, however--I actually LIKE that design for SLI because with two dual slot video cards installed, the extra width between the PCIe x16 slots leaves a gap between the two cards and thus allows for better cooling than the usual SLI designs.
However, if you'd like to forego that airflow advantage, then you could always trade it off in this manner:
1. Try the Asus Rampage II Extreme if you'd like a board more ideally suited for high overclocking.
2. Try the Asus P6T6 WS Revolution if you'd like a tri-SLI capable board. In theory, this board can also run 5 single-slot width video cards, but I don't know what you'd call that.
3. Try the Gigabyte EX58-UD5, which is a very fine offering from Gigabyte that is tri-SLI capable.
Don't know about the MSI, but seeing as they're all $300 anyway, I'd go with Asus P6T Deluxe, Gigabyte EX58-UD5, or eVGA's 132-BL-E758-A1 X58 mobo. Note that of these three, only the Gigabyte and eVGA can run tri-SLI, however. The specs of the MSI Eclipse apparently don't allow it to run tri-SLI either.
When running tri-SLI, the eVGA doesn't leave space for a sound card (you must use on-board sound) while the Gigabyte does, if that matters to you.
Seeing as you had an interest in the GTX 280, I'd keep that tri-SLI door open...
Yeah true, do you think if i build this system with the xfx gtx 260 black edition i will have hardware power to play crysis and farcry 2, also so that i can upgrade to the next series vid card in the next 12 months?
A qualified yes, because you can't play at max settings on a 24"--just turn the settings down for now. You've not mentioned budget or resolution, so I'm just extrapolating here. However, this is the best you can do on a single GPU setup for now.
If I were you, what I would do is build the base by getting a mobo with tri-SLI capability and high overclocking potential, and then just add video cards in the future. This makes sense because you are making such a substantial up-front investment and also because the i7 platform scales well. Once you add the second card, then you'll be in much better shape to turn up the settings. Or you could just use a 19" monitor for now...