depends. rest of your specs are important too.
typically, phenom ii x4 with 6770 is the safer route to take - with a 4 core cpu and a good gfx card.
if the ph ii is a lot cheaper than the 965, you can get the ph ii with a good cooler like xigmatech gaia or coolermaster hyper and take chance with core unlocking and overclocking. your motherboard and psu, case have to be able to support overclocking otherwise you could damage your system.