Computer-construction tips please!

[Jivinjeffjones]

Fallout 3 is coming, which means I must get a system which will kick its ass. Furthermore, my tried-and-trusty laptop is apparently dying. So time has become an issue in finding a replacement.

Having surveyed the premade systems out there and been outraged at their prices for inferior machines, I've decided to make my own. I have friends who have the requisite expertise to put it together for me, but I'm concerned about buying good (and compatible) components. I don't have a helluva lot of knowledge in the field, and it's hard to know which reviews are trustworthy.

I started the same thread at MBTIcentral, and then realized the extreme folly of not consulting a handy population of INTPs. I should mention that my goal isn't so much to get a "good-enough" system for the least amount of money. I want the best system I can get for $5000-6000. At the moment I'm looking seriously at the preliminary list offered by Athenian2000 in post #3:

(Processor) Intel Core 2 Extreme QX9650 $1,030
(Motherboard) ASUS Striker II Extreme $450
(Memory) 2x OCZ Reaper HPC 4GB (2 x 2GB) 240-Pin DDR3 SDRAM DDR3 1333 $700
(Hard Drive) 2x Western Digital Raptor WD1500ADFD (RAID 0) $340
(PowerSupply) Corsair HX1000W $310
(Video) 2x ASUS EN9800GX2/G/2DI/1G GeForce 9800 GX2 1GB (SLI) $1,120

Anyone have any quibbles, further suggestions, recommended reviewers or tips to help me not fuck this thing up? I'm also living in one of the more isolated parts of Australia, if that makes a difference.