I'll start with the motherboard. I am an AMD fan, so I would recommend that, but since you chose Intel first, I assume that is what you want. However SLI loses to Crossfire in almost every test of scaling and nVidia is experiencing a quality control nightmare where their chipsets and components in their graphics cards are failing at alarming rates. Some companies are completely recalling motherboards that have nVidia chipsets. For the moment, you might want to stay away from them.
Here are several good Intel replacements from ASUS that support CrossfireX.
If you are going for a gaming rig, you may consider a Raptor instead of a Barracuda. I have found that even at the rate I download music and movies, 1 TB is too big an amount to pay money for when you could pay a third more for a 10k rpm drive.
Here you go.
You made the right choice on the Thermalright Ultra, which is well known for being extremely good.
Alright, now for the graphics cards, the new 4000 series of ATi cards blows the nVidia stuff right out of the water except for the ultra-high end ones, which the 300$-or-less 4870 can compete nearly on-par with for almost half the cost. Performance-wise, the 4870 is the most powerful, however the 4850 is more cost-effective, registering at less than 200. Both scale extremely well in crossfire and while the 4870 fares better, the 4850 experiences a larger percentage game when running double. I recommend Visiontek.
Here is their 4870 and
here is their 4850. I am currently running two 4870s on my current rig and they are spectacular.
I have had several recommendations against OCZ's power supplies, so while I do not know how widespread defects are, several people I know have had trouble with them. I recommend Thermaltake, Antec, or Cooler Master, personally.
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