Everquest - Online Adventures - Frontiers USA

So do i need to download both the original and this, or do i just download this and all content is there?

No idea what you're talking about. But you're probably likening it to a pc game or the newer ps, which it isn't. PS2 games doesn't utilize downloading extra contents as far as I could recall, even if it can be use to play online, which most people back then often can't because back in those days, connection was mostly on 56kbps dial up and not many have the luxury of a broadband connection. So it's quite safe to assume whatever it is you're talking about the stuff are all already in the game itself.