Should I start Donovan Mcnabb against Indy, Mark Sanchez against Denver, or Alex Smith against Oakland?

I'm leaning towards Sanchez because I have Santonio Holmes and currently working on a trade for Braylen Edwards, but Smith is projecting more points than the other two and, although being on a terrible team, is scoring big points despite several turnovers. I dont think I will mess with Mcnabb and Indy because Sanchez or Smith are more secure choices. What do you think? Also, should I go with Philly Defense against Atlanta or Tennesee against Jacksonville?