Hey!
I'm currently building a Richland APU based system, and I was wondering whether you could overclock the CPU with the stock cooler, or if I should rather get a simple air cooler, like a Cooler Master Hyper 212 EVO?
Go with a cooler, even with it's lower TDP, it's stil at 100w, and overclocking will dramatically increase it, and produce lots of heat. To be honest, if you ever plan any overclocking make sure to always use an aftermarket cooler.
You can increase the wattage draw from a 100w APU up to around 150w easily by overclocking the CPU and the GPU together. I would recommend getting at least a Cooler Master Hyper 212 Evo, Xigmatek Dark Knight II, or an H80 depending on your preference.