For those considering to build a trading machine by your own, I recommended as follows that is actually my current hardware configuration.
[CPU] Athlon64 3000+
[Memory] 184Pin DDR SD-RAM PC3200-1GB(DDR400) Hynix original x2 = 2G
[MotherBoard] ASUS A8V-E Deluxe
[VGA] PowerColor Bravo X700 256MB(PCIe x16)
[Sound] None(On Board)
[HDD] Hitachi Deskstar 7K80 SATA300 (SataII) x2 = RAID1
[Optical Drive] Any
[FDD] Any
[Case] Middle Tower ATX scale that has a good air flow
[Power] 450-500W
[Monitor] DELL UltraSharp 2005FPW /20inch wide/WSXGA+/ 1680x1050
[CPU] Athlon64 3000+
[Memory] 184Pin DDR SD-RAM PC3200-1GB(DDR400) Hynix original x2 = 2G
[MotherBoard] ASUS A8V-E Deluxe
[VGA] PowerColor Bravo X700 256MB(PCIe x16)
[Sound] None(On Board)
[HDD] Hitachi Deskstar 7K80 SATA300 (SataII) x2 = RAID1
[Optical Drive] Any
[FDD] Any
[Case] Middle Tower ATX scale that has a good air flow
[Power] 450-500W
[Monitor] DELL UltraSharp 2005FPW /20inch wide/WSXGA+/ 1680x1050