I will 2nd the props for lxde, I have used it on debian and ubuntu EC2 cloud builds (video CDN) and can attest that it is very light on resource usage.  It would likely be an excellent base for nvOC.

It's also fairly easy to use xrdp w/ lxde to run vnc over rdp so wind0ze users can connect via rdp and not have to install any 3rd party apps for remote access.  https://comtechies.com/how-to-set-up-gui-on-amazon-ec2-ubuntu-server.html