Depends on what you want to do with your server.
Igcn premium would give you latest and the most stable server files on the market. But the price is quite steep.
Remember that unless you have source codes and people who can add extra content to your free files, you'll be stuck with x season and content forever.
I've been on both ends and current going through premium igcn setup which is quite the handful as the content is huge, but I know the effort is worth it as it's the latest thing and any new content updates I will have access to.
As for free files. I would go with louis.