There were a lot of themes covered in the book but i dont know if you're looking for specific Nietzchien themes or the same philosical themes that he covers.
For one that conveys Nietzche's theme of the victory of life over death the closing section of Thomas Mann's 'The Magic Mountain' may be useful. (Nietzche took inspiration from him).
These are also recommended, as Nietzche was influenced by these writers. (These books in particular can be seen to contain similar themes).
Michel de Montaigne - The Complete Essays
La Rochefoucauld - Maxims
Ralph Waldo Emerson - A Modern Anthology
There is also a tone poem entitled, 'Also Sprach Zarathustra' by Richard Strauss that is a musical interpretation of the text.
