Ladell Betts, Selvin Young or Calvin Johnson to start in a Fantasy League with a RB/WR flex position?

Currently I have Betts at that flex rb/wr position. My full bench also has dwayne jarrett, Reuben Droughns, Brett Favre, Dominic Rhodes, James Jones, Selvin Young, and Calvin Johnson, its a 14 team league so things get stretched at a point. Thanks for any advice.