WR, RB, flex question.

[PoolsPats]

Standard non-PPR league:
2 WR, 2 RB 1 WR/RB
I'm playing Jamal Charles in one RB spot and I'm leaning (reluctantly) towards R.Bush over Alex Green in the other RB spot....but I need to fill the other 3 spots.
I have:
Garcon
Jennings
Cobb
S. Rice
M. Austin

Any thoughts would be appreciated.