If your going to dump that much $$$$ I would DEFINITELY wait a few more months. You'll end up Kicking yourself if you don't. All the stuff I read states the same advice – WAIT.
Let the new technology come out - DDRII RAM, PCI Express Video Cards, new SATA standards (i.e controllers updated) and SATA drives (remember I believe only the WD Raptors are 'true' SATA HD's the others are 'bridged' drives from current EIDE), and let's not forget the new Motherboard format (BATX I believe).
If you need some extra speed -- and you need it now -- then you can still pick up some very fast components for a good price. Intel and AMD had major price drops on CPU's. Look at how low the PIV C CPU's currently are.
Some suggestions off the top of my head if you must build one now -- and are not big on OC'ing:
An Asus MB with the Intel 865 chipset (or 875, but that's more $$)
PIV C Northwood CPU - like a 3.0 to 3.2 Ghz. The 'EE's are nice, but they are so much money. Maybe get a 3.2 Ghz CPU and do a conservative OC to get it up to Approx 3.4 to 3.5 Ghz.
1 Gig (2 x 512 MB) of HIGH quality Low latency RAM (Like Corsair or Muskin PC3500). Maybe try the F/S threads in forums for some BH-5 Winbond chips for your RAM (they don't make BH-5 chips anymore). That would be sweet. As you can push these to 225 to 230 + rather easily.
You run a PIV C 3.2 at 16 X 215FSB = 3.44 Ghz. Or A PIV C 3.0 at 15 X 230 FSB = 3.45 Ghz. Using aggressive RAM timings and Increased bandwidth should really help (and run at sync settings for CPU FSB and Memory ex, 1:1). Note that PC4000 and up use higher latencies and if you don't plan to OC too much, then stick with quality PC 3500 RAM.
Strip a RAID config using two SATA WD raptor 37 Gig HD's and then use a good larger EIDE / SATA HD for backup and storage (like a 120 - 200 GB w/ 8 meg cache). With the Asus 875 MB, you can have several RAID configurations at one time (Asus P4c800-E Deluxe I believe is the board).
Then fine tune your set up to make the most out of it. I’m sure many here would help with suggestions.
Next, choose a good video card to suit your needs.
Again, I would not go all out here yet -- as better cards are already on the horizon. You can most likely get by with an ATI 9600 XT or even an Nvidia 5900 non-ultra. The EVGA 5900SE is a sweet card for under $200. Unless your a die-hard gamer or really into gamming and graphics. If that is the case, go with the ATI 9700 Pro or 9800 Pro OR Nvidia FX Ultra cards in 5900 or 5950 Series.
Also note that if you want to experiment in some OC'ing, get a good CPU cooler, like a Thermalright SP-94 heat pipe. That way you don't have to go all out (like H2O or other costly cooling systems) and spend a fortune. It's about $50 plus a good fan. Plus, you can configure the fan to suit your needs (and your noise tolerance).
And of course, a nice case (like Aluminum) is always... well, Nice.
I would also say to use the Money to get nice peripherals instead, like say a Nice 18" LCD monitor w/ DVI interface and fast response times (or get two high quality 17” LCD's -- that would be too cool ). Look into your printing options too.
At least you can use the LCD(s) and / or printer(s) on your dream system a few months down the road.
Lastly -- and very important -- spend the time to do some on-line research on this too. Learn the terminology and get an understanding of how to get the most out of your components for your particular needs. For example, TIMO, Anand Tech, Tom's Hardware, and overclockers.com -- just to name a few -- is a good start. Plus many will be more than happy to share knowledge with you.
I think you'll find out that we are at the limit of the current technology. CPU socket changes are being put into motion. And the new stuff coming out very soon should provide a significant increase in performance.
Taking the time now to learn more, get advice, and buy the right components is a priceless investment. That way, you’ll end up with exactly what you want.
Just something to think about.