Formal:
* Paix et bien: This literally translates to "peace and good," and is the most direct translation of "peace and blessings."
* Que la paix et la joie soient avec vous: This means "May peace and joy be with you."
* Je vous souhaite paix et sérénité: This means "I wish you peace and serenity."
Informal:
* Salut et paix: This means "greetings and peace."
* Bonne chance et paix: This means "good luck and peace."
The best phrase to use will depend on the context and your relationship with the person you are speaking to.