Intel Core i5-9600K
LGA 1151, 3.70 GHz, 6 -Core
Intel Core i5-9600K
LGA 1151, 3.70 GHz, 6 -Core
You get almost no extra performance with the 9600k (between -2% and +2% depending on the application).... I would take the 8600k. 390 chipset works for 9th and 8th generation.
You can take an i7 if you want, but it's not crucial for most games. For video editing, etc.. an i7 could still make sense under certain circumstances.
9600k is basically the same 8600k simply soldered. 8600k is the sweet spot and with the head on you have 10-15° less. And to be honest, beheading is not difficult. The liquid metal is also easy to use. The 8auer youtube shows it and it's easy to do.