New Starters and Rookie RBs not named Bush - best keeper value?

[DERF 0]

I play in a keeper league where we keep 4 guys. My boys are

 

QB - Palmer

RB - SJax

WR - Roy Williams

TE - Shockey

 

Bush is going #1 . With #2, I need a solid RB. Chester, Maroney, Addai, Deangelo, Deshaun are all available. which is the safest pick? guaranteed production this year? most upside pick? keeper pick?