Precisely what I am thinking. The i5-8600K will be a gaming beast, however for those games that benefit from HT the i7-8700K will be a monster. I want the monster.
Why you would consider the i5 is mindboggling to me...
We're on the same page. Sure the i5 will work. But why in god's name would you only want 6 threads of power?
Really, just get an i7. As a current i7 user, you can't go wrong. You don't wonder what if, you get great performance, it's just amazing. A lot of people upgraded from i5s to Ryzen 7s and were blown away. I think they just needed i7s in many cases to alleviate some background tasks.
The i7 is the best line from intel. I don't see a point in penny pinching for an i5/i3. It's WAY too close in price to an i7.
Imagine if a GTX 1080ti/1080/1070 were this close in price.....
The incremental cost of getting in i7... I seriously just don't get most people.
Edit:
I'd more likely recommend a Ryzen CPU than an i5. If you're going to penny pinch, penny pinch. Otherwise, just get the i7.