Since budget is low, maybe AMD Sempron 64bit proccy with ASUS Motherboard K8V-MX will be better suited... 512 MB RAM, 80 GB Seagate SATA Harddisk, Basic Cabinet, Logitech Keyboard+Mouse, a Sony or Liteon CD-Writer/Combo/DVD-Writer as per user needs, 15" Samsung monitor, should be okay... Add for UPS (APC, Numeric, etc), Speakers (as per need, see this months digit for some idea on price and variety in 2.1 and 5.1 sets) while considering final price...
Arun