Well the title says it all. I'm in a predicament. For what it's worth, projected stats are as follows. CJ 11, Jackson 14, Spiller 15. It's the match ups that make this. In the same order, @SD, Wash, KC. Leave link for help.
I like SJax this season based mostly on Jeff Fischer's history with RBs, but for now I bench him if I'm you. His 2.5 YPC performance last week earned him a spot on the bench for now, although I still like him as a starter at some point this season if St Lou can get their offensive line playing better. For now, I definitely put Spiller ahead of him. Spiller looks really good. I would without doubt start him (as long as Jackson is out), especially after last week's impressive performance.
CJ2K is a must start IMO. As somebody who has owned him in the past, I can tell you that he is kind of a roller coaster. One week he'll have 10 fantasy points and the next week he'll go off for 30. Just leave him in and hope for the best.
So I say: go Spiller and CJ2K and don't look back.