Def give up Maclin and Collie in a second. Also see if you can give a backup QB or either TE with a receiver. Don't give up any of your top 3 rbs or white, and preferably not harvin, unless its almost straight up. I think Harvin and Collie is close, probably would do it. Harvin is always getting better and could do just as well as johnson though you never know.
12 Team 4 player keeper no strings. Standard roster/scoring except can start TE at flex
QB Stafford, Kaepernick
RB Foster, McFadden, SJax, Moreno, B. Tate
WR D. Thomas, Nicks, D. Moore, Maclin, A. Brown
TE M. Bennett
D Lions, Dolphins