Platform Upgrade for PCI Passthrough?

So, I am ready to upgrade my aging Haswell 4770K and do PCI passthrough. Which is easier? Ryzen, Threadripper or Intel?
Which chip should I go for? I plan to run Linux and Windows 10. I run AMD GPUs. Windows 10 just shat itself the other day after an update so I figured why not?

Thoughts @wendell? You have the most experience with this. Is there a brand of motherboard and/or model I should aim for as well?

Intel will be easier as far as IOMMU grouping but AMD is coming along.

I am still on the AMD heavy equipment chipsets so I don’t have any first hand experience setting this up on the Zen stuff. Wendell has covered this with videos in the last 6 months.