First of all, how well you can oc a processor is primarily determined by your luck in getting a good chip.
The limitation is really not heat, but the vcore you can safely tolerate.
High vcore is what generates heat.
The first requirement for good cpu(and gpu) cooling is to have a good case.
One with two front 120/140mm intakes.
Any cooler, air or liquid needs a good source of air to do the job.
4790K is a 88w tdp unit.
Here are the TDP guidelines from Noctua:
https://noctua.at/en/tdp-guide
If your case has 160mm available, I would not consider liquid cooling.
My canned rant on liquid cooling:
------------------------start of rant-------------------
You buy a liquid cooler to be able to extract an extra multiplier or two out of your OC.
How much do you really need?
I do not much like all in one liquid coolers when a good air cooler like a Noctua or phanteks can do the job just as well.
A liquid cooler will be expensive, noisy, less reliable, and will not cool any better
in a well ventilated case.
Liquid cooling is really air cooling, it just puts the heat exchange in a different place.
The orientation of the radiator will cause a problem.
If you orient it to take in cool air from the outside, you will cool the cpu better, but the hot air then circulates inside the case heating up the graphics card and motherboard.
If you orient it to exhaust(which I think is better) , then your cpu cooling will be less effective because it uses pre heated case air.
And... I have read too many tales of woe when a liquid cooler leaks.
google "H100 leak"
I would support an AIO cooler only in a space restricted case.
-----------------------end of rant--------------------------
Your pc will be quieter, more reliable, and will be cooled equally well with a decent air cooler.