ATI 5850 (More than enough for WoW)
ASUS P6T SE or P6T Deluxe v2
i7 930 ( If you live near a Microcenter, you can pick up the i7 930 for $200)
2x Samsung F3 500GB (one for OS, other for Data)
Cooler Master HAF 932 or 922, or the classic Antec 900.
RAM (3*2GB DDR3):
http://www.newegg.com/Product/Product.aspx?Item=N82E16820231223
or
http://www.newegg.com/Product/Product.aspx?Item=N82E16820227365
Since you are OCing, a Cooler Master Hyper 212 or a Core Contact Freezer 120mm (will need to buy LGA1366 brackets for the CCF separately)
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Or you can go the i5 route or the AM3 route.
i5: i5 750 ($200)
P55 board:
http://www.newegg.com/Product/Product.aspx?Item=N82E16813131604
AM3 CPU: AMD Athlon II X4 635 ($120)
AM3 board:
http://www.newegg.com/Product/Product.aspx?Item=N82E16813131402
This RAM for the i5/AM3 :
http://www.newegg.com/Product/Product.aspx?Item=N82E16820231277
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I'd personally go for the AM3 for just playing WoW,etc. If you do vid editing,etc I'd go for the i7 930.