You definitely need help, and Schaub is a decent option if you give up Peyton, but I'd look to get better at RB in the deal as well. Consider throwing in any of your RBs for a good upgrade there.
You ARE giving up one one of the top 1 or 2 scoring QBs depending on your format.
Be aware that Warner has spread it evenly between all three of his targets. If this continues it limits the value of Boldin and Fitz...