An air cooler is typically a better, more reliable option than a low end AIO that costs a similar amount. Something like an Cryorig H5 would cost similar to a Corsair H50 I believe, and perform better.
That being said, I have a 6700K overclocked to 4.5 GHz and a basic CM 212 EVO is good enough. Although the fans may get a little louder than some people would prefer.