I think I'm going to end up spending closer to $1200.
Why?
1) Video Card: The Geforce 460 GTX is great bang-for-buck right now. You spend a little more (it's +$91 vs. the 5750HD on either ibuy or cyber), but it appears to out-perform the 5750 HD significantly.
2) Misc.: Went with X58 Chipset and the i7-950 CPU. This meant 6gb Ram vs. 4gb (it appears to me that the RAM multiple of 3 rule that Lenas mentioned only seems to apply to X58; not P55 chipset) so this added some $. I also decided on 1TB HDD vs. 500GB. ANd, I added some extra fans (on cyber; ibuy doesnt appear to offer this option?) and a 12-in-1 media card reader.
I find ibuy is a little more expensive than cyber. It's not a huge difference but here's an example from each builder of the machine I'm aiming for:
$1259 ibuy
$1228 cyber (difference: lower cost and extra fans)
edit 1: oops. i pasted the wrong build in one of my spoilers.
edit 2: If you're firm about staying around $1000, I would try building out you're same system above, but changing to a x58 mobo with an i7-950 and using the 5570 HD. ~$100 more than the build you posted, but a little more bang for your buck.
Like this maybe:
ibuy $1025:
cyber $1012: