Can you explain what mean by multi seat? As far is distros go I would stick to mint as it is much more stable and user friendly. (Source: I’m a Fedora user)
Edit: are you talking about having to separate monitors and keyboards? If so it may not be the best answer. More information. What I would do is install Proxmox and then setup vfio (PCIe pass though) to pass though the GPUs. You will most likely need two USB cards so that each station can have its own USB.
Assuming you get the hypervisor and hardware setup you will likely need to configure some way to keeping everything updated. You can use ansible and a file share or you can just setup automatic updates manually.