choosing guix would mean choosing a smaller community and amount of support for a better language.
I used both NixOS and GNU Guix System, and my conclusion is the same. Things are already hard on NixOS, in Guix it's order of magnitudes harder. Not worth it at all. Besides, there's a flake for using Guix on NixOS, so can just use that.
I found an Ubuntu CD room in the trash, searched about it on the Web, which led me to install it on a low-end PC I had