dear also invest in some good quality ram like corsair and kingston or hynix....also if u can invest in 6600gt ot 6800gt it wuld be a power house provided u invest in a good quality 400w+ power supply from antec or coolermaster or thermaltake.
coz ram and graphic card can be bottelnecks if are not choosed wisely.
if u are more intrested about it PM me.