Pretty much everyone on this site is going to tell you that this Samsung Spinpoint F3 1 TB drive is a better drive, as it uses 500 GB platters. And it's 5 pounds cheaper.
In general, sound cards are unnecessary these days.
The 5970 is pretty much top of the line right now for GPUs, you can't go wrong there.
1000 W is probably overkill for your PSU. Unless you're planning on CrossFiring 2 5970s. You should be fine with around 750 W, though there are calculators out there if you're uncertain. Anything 80 Plus/Bronze certified should be fine, I know lots of people here recommend Antec, among others.
Whoops, meant to explain that a little more, but got distracted.
Most motherboards these days do high quality sound, and usually only audiophiles can detect a difference between the onboard sound and a card. The general recommendation here is to buy the computer without a sound card, and if you're dissatisfied, then buy a sound card.
I was looking when you posted the links you posted the case as the antec 900, you will probably have to go with a antec 1200 the 5970 won't fit on a antec 900.
And the ram you posted is dual-channel, as you're getting a 1366 I7 processor which is triple channel, you will have to get 6gb (3x 2GB)because that's is going to be triple-channel
Now days if you're going to use the computer for gaming you won't need a sound card. Usually the onboard sound is already pretty good. I would just suggest buying a sound card if you build the computer and you're not satisfied with the sound.
I really like the new ATI 5000 series so as I said before I wouldn't wait, and I would get the 5970 now, there's no way of going wrong with a 5970.
Some posts before you said you're going to o.c. a I7 940, just get the I7 920 an o.c it, and save money.
the difference bettween triple-channel and dual-channel is that on triple channel you can get up to 6 sticks of ram, and dual-channel 4 sticks.
If you really do not want to spend that money you will have to drop to a i7 860 which 1156 so you can have the dual-channel, to be honest, I don't know if dual-channel (2 sticks of ram) will work on triple-channel, I think it just doesn't sound right, dual-channel on triple??
I really don't think o.c is necessary with a i7, I didn't o.c. my AMD Phenom II X4 955, neither my 5850 and they handle everything at max without any o.c, now do you think a i7 which is superior, and a 5970, which e beastly superior will handle everything without any o.c.? I really would just o.c in case your computer doesn't run everything the way you expected, I mean like if you don't need it or it doesn't make any difference why loose your waranty?
You really do not need the other 2 GB of ram, I would just go with the 1366 option because that platform will support new intel processor like i9 which the 1156 won't, and memory it's always good to have because it's just going to leave you with more time before having to upgrade again, in my opinion the £60 are worth it if you have it mainly because of future use if you want to upgrade processor.
and what about this HD instead, it's going to save you like 30 bucks so you can save some and get the 1366 system
I don't believe the i7 will hold you back, both are great processors, the main difference for me is the platform which will allow you to upgrade on the future or not.
Any of them would be great, and make a great system, but for that system with 5970 I really would go with a 920(again if I had the money) it's up to you, keep in mind, they're great systems. Are going to upgrade it when needed or just make a new build? If the answer is upgrade, I really think the 920 would be better.
Well then, my last question is, what're some good 1366 motherboards and heat sinks for it? I'm prolly going to be overclocking a bit (I dont want to stress the CPU to the max)
EDIT: I'm looking around for heatsinks and finding a lot of them are only compatible with 775 or AM II, is that the hardware itself that is compatible or can I just work around this by buying some sort of 1366 mounting kit?