I recently assembled a very nice system after conducting extensive research through sites like SharkyExtreme, Tomshardware, PCMechanic & CUSL2. Even on sites where you can custom configure, either they don't offer a component you want or you have to pay too much for certain items. I would suggest you research some known issues of using Windows 2K with AMD processors. The issue is the chipset from VIA. Microsoft and VIA have patches available, but since stability is crucial to a trading workstation I decided to go with Intel. Also I decided against SCSI for several reasons. Too expensive, too noisy and the new 7200 RPM, ATA 100 drives are almost as fast. See StorageReview.com for guidance on this topic. The specs on my system are as follows:
CUSL2-C
PIII, 1 GH cpu
Alpha 6035 Heatsink
CoolerMaster 210 Case (Expensive, but really nice)
Enermax 451 Power Supply
512 MB Cricial 7.5 ns, 2,2,2 RAM (Don't skimp here)
Plextor 16X/10X/40X
Sound Blaster Live Value
Teac Floppy
250 Zip
3COM 3C905C NIC
Matrox G450 32 MB
(2) Sony G400 Monitors
Windows 2000 Pro, OEM (Ebay)
Total cost approx. $3300
Assembly time w/ SW installation was one full day.
The benefit of this approach is that you know everything about the machine you are driving, and this allows you to tweak the BIOS for the right balance of performance/stability. Any support you might need is available on a few key websites. This eliminates the need to endure long hold times and receive less than ideal advice. There is also the satisfaction and pride of your accomplishment. Good luck and good trading!