Can you post both of your rosters? It would help us see what we are working with.
Initially, I would not take that trade. Beanie is injury prone and Hightower is in a Shanahan offense, which means his place as starter all 16 games is maybe about 65% likely. He's just getting rid of junk for Peterson. Plus, both of their values doesn't equal Petersons'.
QBs: Philip Rivers and Mark Sanchez
RBs: Adrian Peterson, Mark Ingram, Ben Tate, Knowshon Moreno, Bernard Scott, Kendall Hunter (both of the latter two recent acquisitions)
WRs: Greg Jennings, Dez Bryant, Sidney Rice, David Nelson (still smarting over losing Britt for the season)
TEs: Jason Witten and Dustin Keller
K: Sebastian Janikowski
QBs: Matt Schaub and Cam Newton
RBs: Darren McFadden, Shonn Greene, Beanie Wells, Arian Foster, Tim Hightower
WRs: Hakeem Nicks, Mike Williams, Miles Austin, Lance Moore, Denarius Moore, Torrey Smith
TE: Jimmy Graham
K: Mason Crosby