To have your Nix-based setup reproducible across different OS (Arch, Debian, Ubuntu, WSL2, MacOS, and NixOS), and have an extensible base config that can be customized to different situations, the go-to framework is home-manager (not NixOS, which only works on NixOS, or NixOS on WSL 2).
https://github.com/nix-community/home-manager