I vote for I5-8600K plus an overclock.
You should be able to reach 5.0 which is as good as it gets for gaming.
Not so bad for editing either. I would rather delay a batch processing run a bit in order to avoid any hicckups because of a slower core.
As to cooling, pay attention first to your case.
Any cooler needs a good source of fresh air to do it's job.
I think two 120/140mm front intakes should do it.
For cpu cooling, there are 4 ways to go.
1. Buy a modest tower type cooler like a scythe kotetsu for $35.
Here is a review:
http://www.silentpcreview.com/article1391-page1.html
Pay attention to the end comparisons and the balance of cooling with noise.
You may need to give up a multiplier or two with this approach.
2. Buy a top end air cooler like a Noctua NH-D15s or NH-U14s. About $80.
Here are the noctua TDP specs:
http://noctua.at/en/tdp-guide
You will get max overclock with this.
3. Buy a custom liquid cooling setup. Probably in the $250 range, I am no expert on this.
I would not buy a aio setup, they are in the $150 range and cool no better than #2 above.
4. Spend a bit more on your cpu and have it delidded. About $25. You will lose the intel warranty, but your temperatures will go down by some 10-15c.
My take..... option #2.