Welcome to OCC

The Build you've laid out looks Very Good

There will always be a 'but' or 'however' though

1. I've never recommend the 560Ti-448 to anyone for a single reason: Price. The GTX560Ti-448 are priced really close to the GTX570s but their performance aren't worth the -$30 price tag. If you look at reviews, the 560Ti 448 seems to be very close to the GTX570. This is however not true since you'll have to Overclock the 560Ti 448 greatly to even achieve the same or better performance then a
stock GTX570. It has no chance competing with an Overclocked GTX570 and I (and many others here) can tell you that the 570 is a hell of a card in terms of Overclocking.
In short, if you could afford the 570, don't bother looking at the 560Ti 448. Newegg has a sweet deals for them with some having a 20% discount until 4/11.
Also, Do you really need SLI? If you're not planning on doing Multi-monitor setup, I advice you to keep away from SLI. SLI could cause issues with games (not always but sometime) and you won't be getting 2x the performance with two cards but 2x the power draw. If you're planning on gaming on a single screen, I recommend getting a single GTX680 instead and save the extra money.
2. If you're using this rig exclusively for gaming, you wouldn't need 16GB of RAM. 8GB is plenty for a gaming rig and SB doesn't support Quad Channel so you'll only need a Dual Channel kit.
Go with these
G.Skill RipjawsX 8GB instead of the 16GB variant.
3. If you plan on sticking with SLI (which I wouldn't recommend unless you're doing multiple monitor setup), I suggest you change the PSU for a 850W unit. I tend to stick with Corsair or Seasonic products since I've never had any units by them fail. Something like the
Corsair HX850 should fit in nicely (it's an 80+ Gold product btw. They just upgraded it)
4. Instead of the Antec 300, I suggest you look on something with some more serious airflow, especially if you insist on doing SLI. I recommend something like the
CoolerMaster HAF 932 Advance or
NZXT Phantom (Although the HAF 932 is cheaper when you consider that it has all fans fitted in whilst the Phantom only has 4 fans fitted in).
Here's what I'd recommend you to get (Newegg prices):
i5 2500K - $219.99 ($10 Newegg Gift Card)
ASUS P8Z68-V Pro/GEN3 - $209.99
G.Skill RipjawsX 8GB - $46.99
ASUS GTX 680 - $499.99CoolerMaster HAF 932 Advance - $139.99Corsair TX750V2 - $104.99 ($89.99 after MIR)Crucial M4 128GB - $159.99
Seagate Barracuda 2TB 7200RPM - $129.99 (The LP 1.5TB you've chosen seems to be deactivated already)CoolerMaster Hyper212 Evo - $34.99 (Newer Version)Lite-On iHAS124-04 24x - $17.99 (Better spec, Same price)Total: ~$1565 ($1550 after MIR)
Hope this helps
Edited by vandreadstriker, 06 April 2012 - 06:06 PM.