4k Editing build what?

Have a look at this build. This should be able to handle any 4K you throw at it.

PCPartPicker part list / Price breakdown by merchant

CPU: AMD - Ryzen 7 2700X 3.7 GHz 8-Core Processor ($309.89 @ Amazon)
Motherboard: Gigabyte - B450 AORUS PRO WIFI (rev. 1.0) ATX AM4 Motherboard ($94.89 @ OutletPC)
Memory: Corsair - Vengeance LPX 32 GB (4 x 8 GB) DDR4-3000 Memory ($262.99 @ Newegg)
Storage: Samsung - 860 Evo 500 GB 2.5" Solid State Drive ($72.99 @ Amazon)
Storage: Seagate - BarraCuda Pro 4 TB 3.5" 7200RPM Internal Hard Drive ($159.89 @ OutletPC)
Storage: Seagate - BarraCuda Pro 4 TB 3.5" 7200RPM Internal Hard Drive ($159.89 @ OutletPC)
Video Card: EVGA - GeForce GTX 1060 6GB 6 GB GAMING Video Card ($199.99 @ Newegg)
Case: Fractal Design - Meshify C Dark TG ATX Mid Tower Case ($74.99 @ Newegg)
Power Supply: Corsair - TXM Gold 650 W 80+ Gold Certified Semi-Modular ATX Power Supply ($59.98 @ Newegg)
Case Fan: be quiet! - Pure Wings 2 140 61.2 CFM 140mm Fan ($11.49 @ SuperBiiz)
Case Fan: be quiet! - Pure Wings 2 140 61.2 CFM 140mm Fan ($11.49 @ SuperBiiz)
Case Fan: be quiet! - Pure Wings 2 120 51.4 CFM 120mm Fan ($9.99 @ SuperBiiz)
Total: $1428.47
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2018-11-22 03:46 EST-0500

It's also a quiet system with very good airflow system. The case comes with two integrated fans, if it's still loud, you can change the included two fans and buy another two 140mm BeQuiet fans in the future.

I'm a video editor myself and I have to say that the R7 2700X and the 1060 6Gb is quite good for what we need. It also allows me to do some high quality gaming on the side.
 


Why choose ryzen and not intel like the i7 8700k?

 


First of all, you'll be spending an extra 30$ for the CPU and another 40-60$ for a cooler depending if you want to overclock a little bit or not. (considering you still need to buy a copy of Windows, which is more then 100$ unless you're fine with buying an OEM key for 10$ on Ebay).

Secondly, both CPUs will do the job more than well. Video editing software use single-core performance. Whilst it's true that Intel's single-core performance is superior to Ryzen's, it's not by much, and you won't actually feel much of a difference when you're working on it. However, when it comes to your rendering times, you will feel a great difference by going for Ryzen with it's higher thread count, which can cut down rendering times by 20%.

The pros and cons for me were leaning towards Ryzen being a better choice for me, and I would suggest the same thing for you.

However, keep in mind that both CPUs are very good for the job. So there are no wrong picks here.

For reference, if you'd like to go for Intel, here are the amendments:
PCPartPicker part list / Price breakdown by merchant

CPU: Intel - Core i7-8700K 3.7 GHz 6-Core Processor ($339.99 @ Amazon)
CPU Cooler: be quiet! - Dark Rock 3 67.8 CFM Fluid Dynamic Bearing CPU Cooler ($61.79 @ OutletPC)
Motherboard: MSI - Z370 SLI PLUS ATX LGA1151 Motherboard ($89.99 @ Newegg)
Memory: Corsair - Vengeance LPX 32 GB (4 x 8 GB) DDR4-3000 Memory ($262.99 @ Newegg)
Storage: Samsung - 860 Evo 500 GB 2.5" Solid State Drive ($72.99 @ Amazon)
Storage: Seagate - BarraCuda Pro 4 TB 3.5" 7200RPM Internal Hard Drive ($159.89 @ OutletPC)
Storage: Seagate - BarraCuda Pro 4 TB 3.5" 7200RPM Internal Hard Drive ($159.89 @ OutletPC)
Video Card: EVGA - GeForce GTX 1060 6GB 6 GB GAMING Video Card ($199.99 @ Newegg)
Case: Fractal Design - Meshify C Dark TG ATX Mid Tower Case ($74.99 @ Newegg)
Power Supply: Corsair - TXM Gold 650 W 80+ Gold Certified Semi-Modular ATX Power Supply ($59.98 @ Newegg)
Case Fan: be quiet! - Pure Wings 2 140 61.2 CFM 140mm Fan ($11.49 @ SuperBiiz)
Case Fan: be quiet! - Pure Wings 2 140 61.2 CFM 140mm Fan ($11.49 @ SuperBiiz)
Case Fan: be quiet! - Pure Wings 2 120 51.4 CFM 120mm Fan ($9.99 @ SuperBiiz)
Total: $1515.46
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2018-11-22 04:18 EST-0500