Re: Playoff advice needed
I would stick with Eli after seeing what the other Manning did to the Ravens this week. The Ravens are just too hurt to take down the Giants right now. If you are deadset on switching him out, I would go with Sam Bradford. Tampa sucks at pass defense, but is "good" against the run. STL can't seem to run very well anyways, and with Amendola back, he should put up some good numbers.
As for your flex, I would go troll the waiver wire for a better selection. There has to be someone good available with only 2 bench spots per team.