I have done a lot of work to build Coder templates based around Libvirt on my personal repo here, however, those are highly customized to things I want to do and if you're just looking for a jumping off point, there's too much in there that you probably won't need.
To address that, I have created this repo, which aims to provide some help to get you started with some of the things I have been working on, without all the complexity of getting them to work exactly how I like them to.
I current have the examples listed in this section.
This will provide a template and a NiXOS configuration to build a couple .qcow2 files to get you started easily.