So, we are arguing for an old air cooler and an H100i? Not much difference. Close loop coolers aren't that great overall. They're widely used but they don't offer significant cooling over a good air cooler.
Just because it is liquid cooling doesn't mean it's good liquid cooling.
Also, OC is far more reliant on the person performing the OC than the cooling itself. Your knowledge of how to overclock is far more effective in temps than spending money you don't need to spend on a cooler.
Sooo... what do you recommend?
Notice that im going to be cooling an i7 8700k, it is a 3,7 with 4,7 boost. The thing with 7700k
is that the people doesnt recommend to cool a 4,2-4,5 with air cool, specially if you are going to overclock