heatsink/fan cooling keeps you pretty limited on oc'ing. i use to run a hyper 212 with arctic silver 5 thermal compound and 2 120mm exhaust fans on each side of the heatsink of 65 cmf and 19 dba and couldnt get a stable threshhold temp above 3.8ghz when runing prime 95. once i got a corsair h100 (liquid cooling with radiator) i can overclock aloooot higher. suggest you get a corshair h80.

If you already have a GPU why get a APU? You can grab a AMD FX-6300 for a few $ more and get ALLOT more bang for your buck.

I was actually planning on getting a 6670 so I can run dual graphics, but I made a new build.

If you're going to buy a GPU already, get one of the AMD FX series CPUs, not an APU. APUs are amazing for budget builds when you don't have money for a graphics card, but when you're already buying one all it does is decrease your performance. The FX series CPUs are much, much better processors then the APUs.

my friend has an a8-5500 and it plays tf2 200+ fps on max settings so don't worry about getting a decent cpu if you don't plan on playing other intense games.

If you were planning on upgrading in the future, get a new mobo. If you want to stay with amd get an am3+ socket mobo and a 6300 so in the future you can get an 8150 or 8350.

Idk how well apu's oc but from amd's reputation of very oc'able cpu's i'd say you could hit 4 ghz no problem but i should do some research on apu's first

Okay I suggest oc'ing slowly like 100 mhz at a time and see how the voltage and temps stabilize. try to get it to a very comfortable region and don't kill the cpu or shorten its life span. past 60C is playing risky even if the max temp is 75 because it opens up room for system failure and early cpu failure.