30C-ish idle is fine, 80C for 24/7 is a bit high. What is your Vcore voltage and how did you overclock it? You don't need a liquid cooler. I run an i7 4790K at 4.8Ghz (and an i5 at the same speed) on a good air cooler.
you can just throw money at the problem; it's your money after all, but I would want to know why your temps are too high under load. My system runs 82C on Prime95 26.6.
The 212 is a budget cooler, but you should have a lower top end then 80C in normal use full oad.