From what I've read of it on the ubergeek boards and groups, that's a helluva video card for its price point. The gamecrazies in particular love it, and the video editing freaks are no less enthusiastic ... looks to me to qualify as a "best buy".
One thing I'd go with if high-intensity gaming was the machine's primary function - a pair of 70-80Gig 10,000RPM drives in RAID 0 for Operating system, programs, and game play, and a 250Gig or larger 7200RPM drive for storage. With your game running on a 10,000RPM RAID 0 array, you can be in and out of a scene before others even know you've been there ... very, very little chance of getting blindsided while you're loading in.
My preferrence would be to go with 2 mid-upper-end optical drives; one a multi-format, dual-layer DVD/CD burner, the other a highspeed DVD ROM drive ... but its your money I'm spending here
Personally, I'd go with at least an upper-midrange audio solution, too, something with DD/DTS 7.1 support.
When it comes to power supplies, well, there is no substitute for watts you ain't got. The heatpipe solution of that Asus board is great, IMO - but you still should think about moving lots & lotsa air through that case, and that means fans. 500W should be enough - for now ... but later .... ?
And finally to memory - IMO, the best bang-for-the-buck out there at the moment is Kingston's HyperX PC2-7200 DDR2-900 - not quite as mind boggling as Corsair's or OCZ's 1Ghz+ stuff, but nowhere near as pricey; a matched 2Gig kit oughta run right around US$300 -325
Boy, I sure enjoy spending other folks' money
Oh, and flat panels are nice, and getting nicer and cheaper all the time, but for all-around performance, IMO a precision CRT still is the way to go.