Case / PSU - I have built with both and would recommend the Antec DF-85 over the HAF-X. The TX-750 is a 2nd tier unit (AX and HX series are 1st tier) and in a $2k box, I'd do 1st tier. it's $305 for the HAF-X / TX750 .... $275 for the DF-85 / CP-850. If ya stuck on the HAF, move up to a HX or AX series.
MoBo / CPU - Ya spending $405 for your combo. At a $2k budget though, I'd want x16 x16 GFX and that means NF200 chip. Read why here:
http://www.tomshardware.com/reviews/p67-gaming-3-way-sli-three-card-crossfire,2910.html
The WS Revolution will cost ya $60 more
http://www.newegg.com/Product/ComboDealDetails.aspx?ItemList=Combo.642533
Cooler - Liquid Cooling is so outta place on andy Bridge. read this comment on the better air coolers:
http://benchmarkreviews.com/index.php?option=com_content&task=view&id=674&Itemid=62&limit=1&limitstart=5
I think the Silver Arrow represents the ultimate air cooler than can be built and still fit within the constraints of an ATX motherboard and a standard computer case......It's almost ironic that coolers like this are becoming available just as processors transition to designs that may ultimately render them unnecessary; even overclocked to 5GHz, an Intel Sandy Bridge 2600K doesn't need anywhere near this level of cooling. Still, it wouldn't hurt, and as I noted earlier, there are still CPUs out there that can benefit from it.
If ya want overkill, ya can do it w/ the Silver Arrow..... I have built several systems w/ the DF-85, CP-850, WS Revolution, 2600k/2500k and one of them has a Silver Arrow. Was easy fit though did have to rotate the thing 0 degress. Performance is phenomenal and is completely inaudible at 4.8 GHz. But ya can do more than ya need with the Scythe Mugen 2 at half the price.
http://benchmarkreviews.com/index.php?option=com_content&task=view&id=432&Itemid=62&limit=1&limitstart=19
Scythe Mugen-2 SCMG-2000 29.00°C over ambient
Zalman CNPS10X-Performa 29.71°C over ambient
Titan FENRIR TTC-NK85TZ 29.80°C over ambient
Thermolab BARAM 29.84°C over ambient
Noctual NH-D14 (2x 140) 30.09°C over ambient
Cooler - $40 - Scythe SCMG 2100
http://www.newegg.com/Product/Product.aspx?Item=N82E16835185142
TIM - $5 - Shin Etsu
http://www.newegg.com/Product/Product.aspx?Item=N82E16835150080
RAM - Save $20 for the same performance
$75 - (2 x 4GB) Corsair CAS 9
http://www.newegg.com/Product/Product.aspx?Item=N82E16820145324
or spend $35 for lower latency CAS 7
http://www.newegg.com/Product/Product.aspx?Item=N82E16820226178
Thinking of going with 2 GTX 570's instead of 6970's.
At 1920 x 1200, ya can beat the 6970's a lot cheaper .
At $310 each, twin 570's get 873 total fps in Guru3D's game test suite (COD-MW, Bad Company 2, Dirt 2, Far Cry 2, Metro 2033, Dawn of Discovery, Crysis Warhead)....
At $220, the twin 900Mhz versions of the 560 Ti get 862 fps.
At $315, the twin 6970's get 825 fps.
Two of those factory overclocked 560 Ti's will cost ya $440 and easily fit in the $2k budget
This is $1905 .... I have built 4 of these since March with just 1 or 2 items varying ... 3/4 has Win 7 pro 64 ... one had Silver Arrow Cooler (frozencpu.com), 2 had 2600k's, 3 had Plextor Blue Ray 320SA, all had Asus GFX cards. Takes me about an hour if I'm not sleeving cables.
Case - $155 - Antec DF-85
http://www.newegg.com/Product/Product.aspx?Item=N82E16811129087
Case Fans - $15 - Antec Red 120 mm
http://www.newegg.com/Product/Product.aspx?Item=N82E16835209013
PSU - $120 - Antec CP-850
http://www.newegg.com/Product/Product.aspx?Item=N82E16817371024
MoBo - $465 - ASUS P8P67 WS Revolution
http://www.newegg.com/Product/ComboDealDetails.aspx?ItemList=Combo.642533
CPU - incl - Intel Core i5-2500K include din above
Cooler - $40 - Scythe SCMG 2100
http://www.newegg.com/Product/Product.aspx?Item=N82E16835185142
TIM - $5 - Shin Etsu
http://www.newegg.com/Product/Product.aspx?Item=N82E16835150080
RAM - $130 - (2 x 4GB) Mushkin CAS 7
http://www.newegg.com/Product/Product.aspx?Item=N82E16820226178
GFX - $220 - EVGA GTX 560 (900MHz)
http://www.newegg.com/Product/Product.aspx?Item=N82E16814130651
GFX - $220 - Same
HD - $65 - Spinpoint F3 1TB 7200 rpm
http://www.newegg.com/Product/Product.aspx?Item=N82E16822152185
SSD - $300 - OCZ Vertex 3 2.5" 120GB
http://www.newegg.com/Product/Product.aspx?Item=N82E16820227706
BR / DVD Writer - $70 - Asus BC-12B1ST/BLK/B/AS
http://www.newegg.com/Product/Product.aspx?Item=N82E16827135247
OS - $100 - Win 7-64 Home OEM
http://www.newegg.com/Product/Product.aspx?Item=N82E16832116754
Corsair Force 3's (same performance as Vertex 3) introduction this week should knock quite a few bucks off the SSD price.
http://www.tomshardware.com/news/Corsair-Force-Series-SSD-sandforce,12762.html