Need help with RBs WHIR!

[Durango2009]

I have Frank Gore as RB1 and I need to set RB2 from the following.

Jamal Charles : He will split carries with Thomas and is going against tough rush D. @home
Brandon Jacobs: Bradshaws backup and going against mediocre rush D. @home
Donald Brown: backup to Addai and goes up against mediocre rush D. away
Ricky Williams: backup to Ronnie Brown and goes against tough D. @home

I wanna start Charles but if the KC offense gets shut out than there won't be much there. My 2nd option would be either D. Brown or Jacobs. I don't think I'll touch R. Williams.

Thanks for any advice.