I might be getting a i5 7600k soon and also the coolermaster hyper 212 evo. I was planning to either go to 4.2 or 4.0 and was wondering if that cooler would be enough.
Why not try the Coffee Lake cpus?
The i3-8350k is basically a 7600k with a slightly higher base clock and can reach 5ghz in some cases. Even with a hyper 212 evo, 4.5 Ghz should be no problem.
You'll also have an upgrade path to the 8700k in a few years time.