Need help with RB depth

The rules in my league are pretty standard, with the exception of .5 per reception which i don't think is normal (I could be wrong). We play 1 QB, 2 RB, 2 WR, 1 WR/TE, 1 TE and 1 K. Anyway, I need help building some depth at rb, and there is literally no one to pick up on waiver. I considered picking up Bernard Scott in a hope Benson would lose his job but I don't feel too great about that move.  My current lineup is as follows:

QB: Vick
RB: Rice and Foster
WR: Welker, DeSean Jackson, Wayne
TE: Vernon Davis
K: Gostkowski

On my bench I have:
S. Moss
K. Walter
O. Daniels
D. Henderson
C. Taylor
K. Orton

Chester Taylor and Devery Henderson are pretty useless. What rb is of equivalent value to Walter? There are several guys in my league who are pretty thin at receiver so I'm hoping I can capitalize on that.

How many guys are in the league?

Can you pick up a quarterback?

If you can  pick up a lower level QB...I would trade Orton and Walter to someone with an injured QB for a decent RB.

Its a 10 man league. I could pick up a quarterback but its a pretty slim field and I don't even see anyone trading for a QB. Starting QBs in my league are: P Manning, Schaub, Cutler, Rivers, Ryan, Brady, Brees, Romo, Rodgers. Which of these guys are going to be enticed by Orton?

I really like your team the way it is. Keep your fingers crossed that your 2 stud RB's stay healthy, and roll with it. Barring an injury, you only have to plug an emergency back in for the bye weeks. The rest of the season you should be kickin ass.