This is one of the tougher questions I've seen on the forum this week. All those players have boom or bust potential.
I think you can rule out James Jones because you have viable running back options, and it is usually a safer play at flex to go RB.
Ryan Williams I would wait and see on, he simply hasn't been productive yet.
Jackie Battle I really like, but he is in a time share. I do think he is a safe bet to continue getting carries after his great game last week. Norv Turner gave him a game ball last week, but he also gave Matthews a vote of confidence this week, so this is a RBBC which is always concerning.
Chris Johnson finally showed up last week, although it is scary to start him right now because he seems to always run into a wall of defenders. He is being a crybaby about his blocking, but it is true that he isn't getting any. I do think CJ is a homerun threat and a guy likely to get the touches, the only question is can he get the running room.
I'm torn between Battle and Johnson here, but I would go Johnson. CJ is no sure thing this year, but I would play him and hope for another week like last week.
QB: R Griffin III, A Luck
RB: A Foster, F Gore, T Richardson, K Hunter, M Hardesty, A Green
WR: V Cruz, M Austin, P Garcon, S Moss, B Hartline
TE: J Witten
K: Matt Bryant