Looking for a sling bag

I'm currently looking for a new bag for when I travel. I'm open to any recommendations. I would carry my Sony a7c with a prime lens, portable charger, wire, passport, wired earphones in a case and a book. Currently I'm using a Uniqlo dumpling bag to carry these items without the camera but I want something that will be able to help better protect the camera maybe with a bit of padding.

Would a 2-2.5L sling bag be sufficient or should I get something a bit larger?