my suggestion, go for a phenom II processor, i7 if u have the money,
i7:
http://www.newegg.com/Product/Product.aspx?Item=N82E16819115214&cm_re=i7-_-19-115-214-_-Product
http://www.newegg.com/Product/Product.aspx?Item=N82E16819115224&cm_re=i7-_-19-115-224-_-Product
phenom II
http://www.newegg.com/Product/Product.aspx?Item=N82E16819103727&cm_re=phenom_ii_x4-_-19-103-727-_-Product
id lean more towards the phenomII just for pricepoint
decent mobo to support it heres a gigabyte that runs ddr3
http://www.newegg.com/Product/Product.aspx?Item=N82E16813128416
some decent ram if u use the board above id say some ddr3 1333, or if you felt like going overboard u can use 1866
go with a graphics card that supports DX 11, the 5870 is a beast of a card
http://www.newegg.com/Product/Product.aspx?Item=N82E16814102872&cm_re=radeon_5870-_-14-102-872-_-Product
and dont forget hdd's u can get a terrabyte for about 100$, and a full size case to put it all in, oh and power supply probly about a 750-1000 watt should be more than enough.
Essay Pro