Your mixing 1366 parts (uses triple channel memory - multiples of 3) and 1155 (uses dual channel memory - multiples of 2) parts.
Case - Great choice
PSU - It would be a crime not to put a CPX form factor PSU in that case. Antec makes those cases specifically to fit CPX form factor PSU's which run both cooler and quieter than ATX form factor PSU's because of their larger size. In giving it a 10.0 performance rating, jonnyguru writes:
[The CP-850] is completely unmatched by any ATX unit on the market I can think of. You'd have to spend twice as much as this thing costs to find the next best thing, performance wise.
Read here about the "unfair competition" offered by the 1200 / CP-850 combo
The above is an obviously unfair advantage for the CP-850... but what of it? Antec has used an integrated systems approach for its CP-850 and its best cases, and if that approach is an advantage over all other case/PSU combinations, then, all the more power to Antec .... For the quiet-seeking computer gaming enthusiast, the CP-850 (along with any of the three compatible cases) is something of a godsend. Fantastically stable power, super low noise at any power load, long expected reliability due to excellent cooling, modular cabling, and all at a price that's no higher than many high end 6~700W models
$115
http://www.newegg.com/Product/Product.aspx?Item=N82E16817371024
The 850 is good for any pair of GFX cards up to the GTX 570 in SLI / 6970 in CF. There's also a 1000 watt version which I'd use with twin 580's
$ 150
http://www.newegg.com/Product/Product.aspx?Item=N82E16817371036
MoBo - Im not sure what it was that attracted you about the Sniper.... if it was the x16 x16 GFX card support ..... I'd suggest the Asus WS Revolution .... I can't recall seeing a MoBo so soundly trounce the competition as the WS does to the UD7
http://www.tweaktown.com/reviews/3795/asus_p8p67_ws_revolution_intel_p67_express_motherboard/index.html
http://www.newegg.com/Product/Product.aspx?Item=N82E16813131714
If ya think ya need Z68 ..... I don't see the need but see here to decide:
http://www.ukgamingcomputers.co.uk/difference-between-h67-p67-z68-and-h61-chipsets-a-22.html
Ya wanna get a GEN3 Z68 .... I like the ASUS P8Z68-V PRO/GEN3
http://www.newegg.com/Product/ProductList.aspx?Submit=ENE&DEPA=0&Order=BESTMATCH&N=100006519&isNodeId=1&Description=asus+Gen3&x=0&y=0
CPU - Why the 2600k ? .... using apps that need HT like video editing, CAD, rendering etc ? If not the 2500k will save ya 100 bucks while giving same performance and running about 7C cooler when OC'd to 4.8GHz
Cooler - The 212 is a great budget cooler .... but all other components scream "not a budget system"
$30 - Hyper 212
$50 - Scythe Mugen 3 (5-7C better temps than 212
$80 - Thermalright Silver Arrow (7-10C betetr than 212)
SSD - Maybe ya wanna move up a tier or 3 (120 GB SSD's srtart at Tier 3 performance). I'd do the Mushkin for a 3 tier performance increase and $5 less
http://www.tomshardware.com/reviews/ssd-nand-reliability,3021-6.html
Tier 3
Mushkin Chronos Deluxe 120 GB ($210)
http://www.newegg.com/Product/Product.aspx?Item=N82E16820226225
OCZ Vertex 3 Max IOPS 120 GB ($250)
http://www.newegg.com/Product/Product.aspx?Item=N82E16820227714
Patriot WildFire 120 GB ($205)
http://www.newegg.com/Product/Product.aspx?Item=N82E16820220599
Tier 5
Intel SSD 510 120 GB ($280)
http://www.newegg.com/Product/Product.aspx?Item=N82E16820167042
Tier 6
Adata S511 120 GB
Corsair Force GT 120 GB ($215)
http://www.newegg.com/Product/Product.aspx?Item=N82E16820148448
Crucial m4 128 GB
Kingston HyperX SSD 120 GB
OCZ Vertex 3 120 GB
GFX Card - Ya didn't have any
Guru3D uses the following games in their test suite, COD-MW, Bad Company 2, Dirt 2, Far Cry 2, Metro 2033, Dawn of Discovery, Crysis Warhead. Total fps (summing fps in each game @ 1920 x 1200) for the various options in parenthesis (single card / SL or CF) are tabulated below along with their cost in dollars per frame single card - CF or SLI:
$ 220.00 6950 (479/751) $ 0.46 - $ 0.59
$ 240.00 6950 Frozr OC (484/759) $ 0.50 - $ 0.63
$ 205.00 560 Ti (455/792) $ 0.45 - $ 0.52
$ 320.00 6970 (526/825) $ 0.61 - $ 0.78
$ 215.00 560 Ti - 900 Mhz (495/862)
$ 0.43 - $ 0.50
$ 340.00 570 (524/873) $ 0.65 - $ 0.78
$ 480.00 580 (616/953) $ 0.78 - $ 1.01
$ 725.00 6990 (762/903) $ 0.95 - $ 1.61
$ 750.00 590 (881/982) $ 0.85 - $ 1.53
The factory OC'd 560's offer the best bang for the buck in both single and SLI / CF situations with 43 cents per frame as a single card and 50 cents per frame in SLI
http://www.newegg.com/Product/ProductList.aspx?Submit=ENE&N=100006519&IsNodeId=1&Description=900Mhz%20560%20Ti&bop=And&Order=PRICE&PageSize=20