Upgrading Core Components - Any Suggestions?

Getting this for an upcoming game. I would like to get the system built by the end of December. I will be over clocking my processor and ram. I was not planning on over clocking my video card since I am pretty noob, so I don't mind spending the extra bucks to have it factory done. I also will be running at 1900x1200 and win7.

Case:
Antec Nine Hundred Black Steel ATX Mid Tower Computer Case
http://www.newegg.com/Product/Product.aspx?Item=N82E16811129021&cm_re=antec_case-_-11-129-021-_-Product

Processor:
Intel Core i7-920 Bloomfield 2.66GHz LGA 1366 130W Quad-Core Processor Model BX80601920
http://www.newegg.com/Product/Product.aspx?Item=N82E16819115202

MB:
ASUS Rampage II Extreme LGA 1366 Intel X58 ATX Intel Motherboard
http://www.newegg.com/Product/Product.aspx?Item=N82E16813131352

Combo Deal:
http://www.newegg.com/Product/ComboDealDetails.aspx?ItemList=Combo.293506

Ram:
CORSAIR DOMINATOR 6GB (3 x 2GB) 240-Pin DDR3 SDRAM DDR3 1600 (PC3 12800) Triple Channel Kit Desktop Memory Model TR3X6G1600C8D
http://www.newegg.com/Product/Product.aspx?Item=N82E16820145224

PSU:
CORSAIR CMPSU-850HX 850W ATX12V 2.3 / EPS12V 2.91 80 PLUS SILVER Certified Modular Active PFC Power Supply
http://www.newegg.com/Product/Product.aspx?Item=N82E16817139011

Combo Deal:
http://www.newegg.com/Product/ComboDealDetails.aspx?ItemList=Combo.293279

Video Card:
ASUS EAH4870 DK/HTDI/1GD5 Radeon HD 4870 Dark Knight 1GB 256-bit GDDR5 PCI Express 2.0 x16 HDCP Ready CrossFire Supported Video Card
http://www.newegg.com/Product/Product.aspx?Item=N82E16814121291

I am planning on getting two cards and is the reason I am going with the rampage based on Tom's Benchmark. I also am going with the HD 4870 based on their benchmarks, which seem to edge out two gtx 260 cards.

Do you see anything I should change or buy differently. I already have memory so I am not buying any of that. I am really just looking to upgrade these core items.

Are you sure you want that video card? I mean....The 5800 series are out, but anywayz its gonna be sick build. Maybe get some dust filters for the Antec 900. It doesn't come with front dust filters.

I'd always thought that 2 GTX 260s were better than 2 4870s. If you're gonna go with 2 4870s later, might as well get a 5850 or 5870. The 5870 might not fit the Antec 900 if you decide to get that down the line, but I'm not sure.

Two GTX 260 SLI I think may be slightly better at the highest settings at 1900x1200 8xAA, but I believe it is relatively small. Is there really any big difference between the two if they both have the same output?

Is the 5800 series really that crazy in size that it wouldn't fit in my antec? Antec I feel is a pretty good size case. My only problem with the 5800 is that they are 400 right now. I don't really want to drop 400 on a card. I guess you are correct that two gtx 260 or HD 4870 would cost around 320. Maybe I should order the card in about a month and a half for the price to drop a little bit?

The Antec 900 is a tight sqeeze for most new cards. That case has been out for years now, before the age of monster video cards like the 5870. But I think it should fit the 5850. I have that case and it barely fits
my GTX 260s. You can't install hard drives where they're installed.

Any case recommendations to fit the larger size vid cards?

So I have been doing a lot of research and reworking my rig. I am going to upgrade the entire thing now and give the old computer to my parents. Here is my updated specs. I guess I really want input on a few things:

1) The MB I should get. I was going back and forth between the EVGA 758-TR and the ASUS P6t Deluxe v2. I read a bunch of reviews and the benchmark for the EVGA 758 seems to run not nearly as nice as the ASUS P6t. However, Tom did not recommend the old Asus P6T version because of graphics card spacing (was only 1 line spacing). Correct me if I am wrong, but I believe from the pictures the V2 offers an extra space now. This allows the card to breath/overclock better when in SLI/Crossfire mode. Link to both cards below:
EVGA - http://www.newegg.com/Product/Product.aspx?Item=N82E16813188046&cm_re=EVGA_X58-_-13-188-046-_-Product
ASUS P6T - http://www.newegg.com/Product/Product.aspx?Item=N82E16813131365&cm_re=asus_p6t_deluxe-_-13-131-365-_-Product

2)Heatsink - Is it really necessary if I am going to overclock? I am planning to put my i7-920 to around 3.8ghz-4.0ghz. I have never installed a aftermarket heatsink so I am a little worried. If I get, for example, an Prolimatech Megahalems heatsink does this really impact my computers performance with the case I will have (Cooler Master HAF 932)? Since I have never installed one I get worried and rather leave it alone if not necessary.

3) Ram - I see a lot of the Tom's Hardware benchmarks using the Corsair dominator ram. I don't really see the difference between that and OCZ Gold. They look to have the same speeds and specifications. What is the difference and is it really worth the extra 110.00? Also, what do you think about going with platinum for only $34.00 more than the gold (also looks faster than the dominator). It looks to have a faster speed, but is it worth the money if I plan to upgrade to 12gbs?
OCZ Gold - http://www.newegg.com/Product/Product.aspx?Item=N82E16820227365&cm_re=ocz_gold_6gb-_-20-227-365-_-Product
Corsair - http://www.newegg.com/Product/Product.aspx?Item=N82E16820145224&cm_re=corsair_dominator-_-20-145-224-_-Product
OCZ Platinum - http://www.newegg.com/Product/Product.aspx?Item=N82E16820227381&Tpk=OCZ%20Platinum%206GB

4) Video Card - I am planning to get a Radeon HD5850, but are there any factory overclocks out there yet? Do you need to do this manually? I haven't done it before, but I am pretty sure there are some simple guides out there to do it. I would prefer factory overclock since I will run Crossfire and I hear you can't have two different speeds on your cards. Mb this is too easy to do yourself and someone can point me to a good guide.


Computer Build
CASE: COOLER MASTER HAF 932 - http://www.newegg.com/Product/Product.aspx?Item=N82E16811119160

Core: Core i7-920 - http://www.newegg.com/Product/Product.aspx?Item=N82E16819115202

MB: ASUS P6T Deluxe V2 LGA 1366 Intel X58 ATX - http://www.newegg.com/Product/Product.aspx?Item=N82E16813131365

Ram: OCZ Gold 6GB (3 x 2GB) 240-Pin DDR3 SDRAM DDR3 1600 (PC3 12800) - http://www.newegg.com/Product/Product.aspx?Item=N82E16820227365

PSU: CORSAIR CMPSU-850TX 850W - http://www.newegg.com/Product/Product.aspx?Item=N82E16817139009

Video Card: SAPPHIRE 100282SR Radeon HD 5850 - http://www.newegg.com/Product/Product.aspx?Item=N82E16814102857&cm_re=radeon_hd_5850-_-14-102-857-_-Product

Hard Drive: Western Digital Caviar Green WD6400AACS 640GB 7200 RPM 16MB Cache SATA 3.0Gb/s 3.5" Internal Hard Drive - http://www.newegg.com/Product/Product.aspx?Item=N82E16822136298
**I already have a 1tb external HD so I really don't care to get bigger, but rather it be faster.

Disk Drive: SAMSUNG Black 22X DVD+R - http://www.newegg.com/Product/Product.aspx?Item=N82E16827151175

It's my personal preference here. I'd take the Asus delux over the EVGA. They will both do the job, but I've had nothing but good experiences with Asus.

If you're going to OC that high, yes, you'll want an aftermarket cooler. They aren't too bad put on. Just remember to do it before you mount the motherboard.

OCZ has reasonable priced products. With the Corsair dominators, you are overpaying for their name. They make good performance RAM, but they charge too much for their name. Go with the OCZ gold.

Here's some help on OCng your graphics card.
http://www.overclock.net/faqs/1355 [...] -card.html

If you can deal with a little smaller drive, the 500GB spinpoint f3 is faster than the WD caviar black.
http://www.newegg.com/Product/Prod [...] -_-Product

Yes. There are benchmarks for several different performance aspects. The majority have the spinpoint f3's a little faster than the caviar black. You can check them out here.
http://www.tomshardware.com/charts [...] ks,50.html