Drop Pettis for?.... HELP

So I have Pettis and I still think he has upside as, what I thought was, the top guy in San Fran. Am I wrong to think this? Should I drop Pettis for any of the following guys on waivers? (PPR)

DeSean Jackson
John Brown
Michael Gallup
John Ross
Malcom Brown

P.S. Where can I find the mailbag thread?