* "L'amour et la paix" (pronounced: la-moor eh lah pay)
This is the most literal translation, using the feminine noun forms of "love" and "peace".
You could also use a more poetic phrase:
* "Amour et paix" (pronounced: a-moor eh pay) - This removes the articles and sounds more like a slogan.
Both options are grammatically correct and commonly used.