Had I not gotten the hernia, this could have worked for me.
http://www.board.crossfit.com/showthread.php?t=25531
You'll need a moderately large work capacity and CF days would need to be hand picked/tailored to not conflict with the SS workouts. For example, Helen and Cindy don't clash with SS like Linda or Lynne do. Alternatively you could do Tabatas or HIIT.