For each of your VMs you can install either Enterprise Desktop or Workstation for Linux depending on what your requirements are. The latter is a mini-terminal server giving you 4 NoMachine virtual Linux desktops running in your own KVM instances. Enterprise Desktop on the other hand will give you access to the full local desktop running in each VM. They both install out-of-the-box and are pretty-much hypervisor-agnostic.
Our upcoming product, Virtualization Server, will take away all of the frustrations of having to provide centralized access to these multiple virtual desktops you want to set up, and then manage using virt-manager.
Simply put Virtualization Server will provide seamless integration with all VMs in a virtualization host.
You can read more about it here, https://www.nomachine.com/FR11N03239.