Question about Intel Core i7-8700K

Hello Saccara, OC is not actually planned. The case is this one:
Cooler Master MasterBox MB600L (Midi Tower)

Hello.
It depends on whether OC is planned or not and how much space is available in the housing.

For normal use, for example, the following is recommended:
be quiet! Dark Rock 4 (15.94cm)
Or
be quiet! Pure Rock (15.50cm)
Or
Noctua NH-U12S (15.80cm)
If OC is planned:
Noctua NH-D15 (16.50cm)
Or
be quiet! Dark Rock Pro 4 (16.28cm)
Or
Scythe Cooler Mugen 5 PCGH (15.40cm)
Or AIO Wakü e.g.
Corsair H115i Pro
These are only my suggestions, there are of course other products that fit.