Who whould you start, 10 team league?????

In my league we start 1 QB, 2 RB, 2 WR, 1 TE, 1 WR/RB, 1 QB/RB/WR, 1 DEF, 1 K

My players are:

QB-- Aaron Rodgers (@ SEA), Peyton Manning (HOU), Ryan Fitzpatrick (@ CLE)

RB-- Steven Jackson (@ CHI), Demarco Murray (TB), Michael Bush (STL) (just picked him up in case he starts), Doug Martin (@ DAL), Willis Mcgahee (HOU), and both Ahmad Bradshaw and Rashard Mendenhall are out.

WR-- Victor Cruz (@ CAR), A.J. Green (@ WSH), Steve Smith carolina (NYG), Vincent Jackson (@DAL)

TE-- I only have one Vernon Davis (@ MIN)

DEF-- just Chicago Bears (STL)

K-- just Matt Prater (HOU)

Im having trouble deciding who to start. Should I put a RB or WR at flex? Should I play a 2nd QB at my offensive player spot?

Thanks!!