Who to start in 4th flex spot?

[rack04]

My team:
QB Brett Favre vs Bal
WR Randy Moss vs Ten
RB Steven Jackson @ Jac
TE Heath Miller vs Cle
W/R Brandon Marshall @ SD
W/R Clinton Portis vs KC
W/R Thomas Jones vs Buf
--empty--
K Josh Scobee vs StL
DEF Minnesota vs Bal
BN Ronnie Brown Bye
BN Tony Romo Bye
BN Mike Bell vs NYG
BN Martellus Bennett Bye
BN Chris Chambers vs Den
BN Sidney Rice vs Bal
BN Kevin Walter vs Cin

Start 1 QB, 1 WR, 1 RB, 1 TE, 4 Flex, 1 K, and 1 Def

The decision that I'm trying to make is who to start in the 4th flex position.

Sidney Rice vs Bal
Kevin Walter vs Cin
Mike Bell vs NYG

Typical scoring system with 1 pt per reception