If you think you can get Chris Johnson for BJ+WR3, that would be by FAR the best deal of the three you proposed, and a win for you. If you want Steven Jackson, I wouldn't even ask for a filler, and BJ+WR3 for Deangelo almost tilts in favor of the other guy.
One thing you should consider with all of these backs is team record. You're talking about getting rid of the stud back for a 3-0 team, to pick up a guy from an 0-3 team, in all three cases. I prefer RB's from winning teams because they are much more likely to A. be in position for goalline TD's, and B. pick up junk, run-out-the-clock yards. So unless you can get Chris Johnson, I wouldn't try to deal BJ.
12 team H2H league, standard scoring, no PPR.
QB: Cutler, Kitna
RB: All Day AP, CJ2K, F.Jax, R.Brown, S. Greene, Dixon
WR: G. Jennings, Roy Williams, M. Williams (sea)
TE: J. Tamme
K: Hartley, Carpenter