First off that is a fair amount of horsepower for that resolution on those games unless you want ridiculously high framerates.
As for overclocking the CPU to 5GHz, while it's not an enormous OC, it's more than a pedestrian OC. That cooler is unlikely to get you there. By 5GHz, I assume that's not a single core at 100% usage, you want it to run that clock with all 6 cores at 100% at 5GHz right? If this is the case, you will most certainly need something bigger to keep your temps in check. You should be looking at a good 240mm AiO or better. Or a very good / large air cooler.
A lot of people make the mistake of seeing water cooling (regardless of size) and they automatically think awesome temps and quiet. In many case the latter is out the window right away as the pumps can be quite noisy on AiOs. That is a very small radiator so you aren't going to get very good cooling efficiency if you intend to overclock, just not enough surface area.