Both have great matchups but Thomas has been more consistant, even sharing with 2 other backs. I'd say McCluster has more upside but Thomas is the safer pick. If I were you I would gamble on McCluster. Only a difference of a point or two avg. right now anyway.
1QB, 2RB, 2WR, 1 WR/TE, K, DEF
Standard 12-Man Auction League
QB - C. Newton, J. Flacco
RB - R. Rice, M. Jones-Drew, M. Tolbert, C.J. Spiller, D. Karim
WR - L. Fitzgerald, W. Welker, J. Graham, L. Moore
K - S. Gostkowski
DEF - Jets, Titans