AIO watercooling isn't stressful at all, it's a breeze. I would only recommend a Noctua cooler for an air cooled K series chip, ESPECIALLY if you are overclocking with it. But if you don't want a beefy heatsink that gets gummed up with dust, and have to blow the dust out of as often, get an AIO from corsair or NZXT or another reputable brand.