I guess Gibson got 17 looks last week which is huge but only pulled down 5 receptions (didn't see the game). I think I read that he missed two passes in the end zone. Avery on the other hand has seen the end zone this year. Having Boller play can't help anyone but it's the Rams so what could it hurt.
The safe play is Avery. The higher risk with the higher reward is Gibson.
Unless you feel like taking the gamble, I would go with Avery until Gibson starts seeing TDs.
[12 Team league. Starts 1QB,3WR,2RB,1TE,2WR/RB,1K,1Def
QB: Big Ben, Cutler
RB: Rice, Best, R Williams, Woodhead, J Forsett, McGahee
WR: R Wayne, D Jackson, S Smith (NY), Gaffney, S Smith (CAR)