Have you looked at Guix? I love it because it uses Scheme instead of Nix as its language, but I realize not everyone likes Lisp as much as I do. Also, I found the documentation easier to follow. Since it is a GNU project, you will need to install a third party channel (repo) if you need proprietary drivers/firmware. If you do, check out SystemCrafters’ install image, which has firmware on the image so you can at least boot it.