It hardly Goes Unlocked & stabkle with 3X & 2X amd CPUS ! so why dont you get x4 950 BE & get your self Out of unlocking & ocing Trouble & experience Pure Quad Core , i recommand Phenom 965BE if u ahev enough money ! its greatest AMD Option or phenom 950 !
Unlocking is Risky , you may Fail & after unlocking 3rth or 4rth core you get your 4rth Core Unstable ! but if you still wanna accept this risk then from 2 Listed CPU
AMD Phenom II X2 555 Black Edition 3.2GHz is better because Phenom is better than Athlon ! compare them at ANANDtech.com