Re: just looking for some advice.
The X2 5000+ should be able to match the 6000+. If not, it's not noticeable. Plus, the 5000+ runs cooler, because it uses the 65nm, as opposed to the 6000+'s 90nm.
If you are overclocking though, you should get an aftermarket cooler. And I would suggest the Arctic Cooling Freezer 64 Pro. It's only $20 at newegg.com.
Unfortunately, I'm not familiar with AMD's way of overclocking, but nagasama and Apokalipse are. You should shoot them your questions.
3770K | ASUS STRIX GTX 1080 | DDR3-1600 16GB | CORSAIR 650D | CORSAIR HX 850W | CORSAIR H100 | SOUND BLASTER Z | ASROCK EXTREME4 GEN3