Your query would be better if in the 'General' topic folder. A Mod may see fit to move, but please don't double-post.
If you want a gaming setup, you would need at least a dual-core (or equivalent) processor running around 3 Ghz, with PCI-E video slot of the 16x class for SLI or Crossfire. And up to 4 Gb of system memory to match the CPU. A PSU of at least 600 watts would be in order, as well as a hdd of the SATA class of around 300 Gb. On-board sound is decent, but if you want true 5.1 or 7.1 sound setup only a sound card will do.
If there is on-board video, look for another model/brand. On-board video will never come close to a decent video card! And why pay for a feature you will never use?
F@H.. to solve mankind's maladies.. in our lifetimes!