The one that says version 1.7.5 is the latest (for now). You don't need both, I left the second in case the latest version doesn't work.
If you get lifetime you'll get updates as long as I release them (or get hit by a bus).
Itch should notify you by email when there's a new update. You should also get emails when I make a new dev post. If you join Discord you can get notified there too.