Mitchell is becoming overrated. He is a number 3 or 4 guy and is somehow being named with elite defensemen (Jovocop is not elite either).
If I had my choice, it would no doubt be Redden, but I don't think that is realistic.
The Pens should be looking at guy like Skrastins, Sarich, Bouillon. This is a pretty decent year to add some solid defensive help.