well amd plan to be now that they have bought ati there plans are too make one chip which integrates both hardcore graphics and cpu.
Core2duo's are faster easier too over clock and use less power look at
and you will see which has the better performance.
This is my recommended build for your budget im in the uk though so im not completely confident about the prices on newegg.com
mobo: abit AW9D-max
Cpu: E6600 (e6420 if you can wait till may-april)
Ram: (2x1gb) g-skills hz (its the black ones lol)
any other parts you want??