I'm currently in the process to build such a setup. Hardware wise I went for AMD TR 292, Gigabyte Designare X399, 32G RAM and my good old Asus Strix 970 GTX and a second AMD Radeon Pro WX7100 for gpu passthrough.
Distro is Suse Tumbleweed with KDE. Bios is updated to F12g and well, xen fails to boot past grub for now. Due to job and family I haven't gotten any further yet. I've also run into cooling issues, as it seems my case needs some serious tuning for todays high spec CPUs it seems. So... it's going to be a project.