+1 for Newegg.com, some items are really cheap and they also got a great shipping.
suggestion:
cpu:AMD athlon 64 3000+(939)
MB: Gigabyte GA-K8NXP-SLI (just release on Newegg.com)
RAM: Corsair 1GB(512*2) PC-3200
Graphic: Leadtek or Gigabyte 6600GT 128mb PCI-E (one is enough for you right? if not, buy 2)
PSU: Seasonic 400W
LCD: ?????(I have no clue)
HD: Western Digital 250GB 7200RPM 8MB buffer
DVD+-RW: I don't care what brand, as long as it's cheap
sound: Creative Sound Blaster Audigy 2 ZS
Mouse, Keyboard: 隨便吧.