Go for the PC first. If you can wait for a few weeks, do it. The new Ryzen generation is about to launch I think, so the prices on the old generation will fall.

Apart from the CPU, consider spending some extra money on a fast SSD drive. Or get 2 of them and put them on RAID 0 (disk striping, you will be seeing 1 disk with the combined space of the 2, and it will be super fast - I assume that since you are using it as a video editing workstation, you are working with huge files)

Also, don't cheap out on RAM. Get as much as you can, and get the faster model. And consider making your CPU/GPU water-cooled, as it will help your machine be cooler and a cooler machine means a faster one!