Well, the book is a proper tome, but the section on Stoics is very concise (as is rest of the book, really), so I'd go for "A History of Western Philosophy" by Bertrand Russell.

The book also gives a good context on where Stoicism arose, so it might be worthwhile to skim the sections before, though there's no need to get too deep with, say, Aristotle's metaphysics.

It's on archive.org: https://archive.org/details/westernphilosoph035502mbp/page/n...