nix-daemon should have no problem running with other service managers — it works with
launchd on OSX too. Running it should be a matter of executing
nix-daemon as root, nothing special there.
You’ll also need build users — these should be in the
nixbld group by default, and there should be at least one per derivation you want to be able to build in parallel. I think the only requirement for these users is to be members of the group, but in terms of good practice these users should typically not own any persistent directories in the filesystem and not be able to log in (since they don’t need it).
If your service manager needs it backgrounded, you’ll need to write a script to take care of that — it will run in the foreground by default.