FF - Playoffs, need RB help

1st round of my league's playoffs is this week, and after losing Westbrook in Week 13, I'm hurting at my #2 RB spot. I picked up Ryan Moats off of waivers last week, but dropped him when Ricky Williams became available.

Moats is still available and I have first waiver priority out of the four teams remaining, however I noticed that Marion Barber is also available. Moats is @ STL this week, Barber is @ WAS.

There is a chance I could grab both of them, but assuming I can only pick up one of these guys, who would you roll with FOR THIS WEEK ONLY.

I put a poll here but I'm looking more for insight, which is much appreciated and any FF questions I'll try to help you with as well.

1 pt = 10 yds rush/rec; 6 pt = TD; -2 FL