Both of my QB's are injured!!!?

I have both David Garrard and Matt Schaub. Garrard is out and Schaub is questionable. The available FA's are Trent Edwards, Cleo Lemon, Marc Bulger, Alex Smith, Daunte Culpepper, Tarvaris Jackson, and Quinn Gray. Who is the best of the worst? I'm holding on to Garrard, who should I trade Schaub for?