Which combo has more value for the rest of the season?

16 team league. I have kevin smith as my RB1 and Rashard Mendenhall/Fred Jackson as my RB2. I am looking to trade for either willie parker or marshawn lynch to get the full carries on 1 team rather than split carries for 2 different teams. My question is which combo has more value for the rest of the season: Lynch/Jackson or Mendenhall/Parker?