Honestly its not that bad. I like that you have Volquez, Greinke and Wainwright, who I think were all underrated. Greinke was probably a good steal. I'm confused why Benoit is on your team. He put up decent numbers last year, but really not worth owning.
I am a big fan of the middle relief game. I'm employing Marmol and Rafael Perez myself. Jones is a massive liability for your ERA and whip, so you need a top middle reliever to counteract him.
If Perez isn't available (because I know Marmol isn't) try and find someone like Peter Moylan (who could be the Braves new closer, or look at Manny Acosta if you really want saves too), Heath Bell, Okajima, etc.
If you really want to add another starter, look towards the popular adds: Saunders, Bannister, Owings, or Erving Santana (home starts only please). Otherwise, wait for Kershaw to get his call up and play the matchups.