I'd try to get a WR for him if I were you. If you have to reach pretty low, I'd consider going after someone with huge upside, like a Jacoby Jones. If you could get Dez Bryant that would be another great option.
You need to target a WR who has the potential to replace TJ Housh if the upside comes around. I've always had trouble with RB for RB trades before the season starts, because everyone just looks back at their sheets to see if they're getting the better end of the deal.
Anyway, I'm not sure that I would want to dump Jacobs if I were in your position. Who will you put in the flex spot? McFadden?
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