I feel like the obvious choice to sit is Smith going against the Niners. My only pause is that Best had a good game against them last year, and that is the role that Smith is playing now.
Forte and Sproles semm like locks to me.
Leave a link and I will leave a detailed answer
RBs- Forte, Sproles, Martin, K Smith, Ronnie Brown
WRs- Welker, D-Jax, Britt, Mike Williams, Lance Moore, LaFell
K- Jason Hanson
Def- Buf D