Waiver and/or trade help

[Paladin0506]

My Team
QB: Donovan McNabb
WR: Andre Johnson
WR: Roddy White
RB: LaDainian Tomlinson
RB: Darren McFadden
Flex: Mike Bell
TE: Chris Cooley
K: Nate Kaeding
D/ST: Green Bay
Bench: Eddie Royal
Bench: Jamal Lewis
Bench: Donald Brown

Free Agents
QB Ben Roethlisberger
RB Julius Jones
RB Cadillac Williams

I plan on picking up Big Ben to in case McNabb can't play, but who do I drop? And is Jones or Williams worth picking up?
Could I try and trade Bell or Brown to the owners of Pierre Thomas or Joseph Addai?

Pierre Thomas Owner
QB: K Warner, T Edwards
RB: C Johnson, P Thomas, F Jones, C Taylor, A Bradshaw
WR: C Johnson, B Edwards
TE: O Daniels

Jospeh Addai Owner
QB: M Ryan
RB: S Jackson, S Slaton, J Addai, K Smith
WR: A Boldin, D Jackson, K Walter, J Morgan
TE: D Keller