You won't really wrong with any combination, unless you sit Johnson (haha). Decker and Manning have built quite the relationship though, and I have been off the Beanie Wells train for a long time. He is just a mid-to-low tier back. If you look at Decker's preseason stats and rapport with Manning, you might change your opinion. Hope this helps.
10 team 1 QB, 2 RB, 3 WR, 1 TE, 1 K, 1 DEF P Manning, RG3 A Foster, CJ Spiller, B Tate, V Ballard, D Williams D Thomas, J Nelson, Mike Wallace, Cecil Shorts, Danario Alexander, D Heyward-Bey J WItten Janikowski 49ers