nixos-config VS archbox

Given that you already have flakeified everything, it's not that hard to pull in a different version of nixpkgs and cherry-pick packages from it. I have a (somewhat complex) setup utilizing this: https://github.com/casept/nixos-config

I also found this project which streamlines the process a little https://github.com/lemniskett/archbox

you mean something like archbox? https://github.com/lemniskett/archbox

If you don't mind the storage penalty, it looks pretty convenient to set up an Arch Linux chroot and use packages from the AUR when you need to: https://github.com/lemniskett/archbox/blob/master/NIXOS_INST...

Nixpkgs itself is several times the size of the base Arch Linux package collection, and by ‘non-unique’ package count, Nixpkgs is also much larger than the AUR. In addition to Nixpkgs, you can find Nix packages in several community ‘overlays’ for Nixpkgs as well as Nix's own user repositories.

You can check to see whether everything you currently use/need is conveniently available for NixOS in a comprehensive-ish way through the combination of these two web search tools:

• for Nixpkgs/NixOS: https://search.nixos.org/packages?channel=21.05

• for NUR: https://nur.nix-community.org/

NixOS also includes native Flatpak support.

Fwiw, packaging most things for Nix is very easy. I left Arch in ~2010 because at the time the package management stack and default repos on Arch basically sucked compared to most distros I'd used and liked, and from then on I decided that if I wanted software that wasn't in my distro's repos I'd just package it myself. After taking a little time to learn the tools on whatever distro I was using, I never missed Arch or the AUR. Compared to other distros, packaging normal software from source is usually exceptionally easy on NixOS.

If I were you I'd just dive right in and hit Nix's channel on Matrix with the Nixpkgs manual in hand if I found something I wanted to use that wasn't already packaged. But you can fall back on the options outlined above.