If you have read here for any length of time, you would know to never sit your studs. You play CJ every week, even if they are playing the Bears 1985 Defense. People try to get too cute going with this is a better matchup against this defense kind of crap and most (not always) of the time, you lose doing this.
With that being said, start CJ and I like Rice against Cleveland. Peterson had much better numbers against Cleveland than he did Detroit. So, I see playing the Browns as a good matchup for any RB. You can't go wrong playing Brown or Rice. So, just pick one and don't fret over the pick. They will probably have about the same numbers come Sunday.