I dropped him this week for Shorts. His upside would be great if the offense was better. I have had him on my bench since he came back and have been disappointed every game. I would go for Hilton then Alexander.
You could make a case for any of the wideouts you mentioned as candidates to replace Britt but I would swing for the fences here and grab Blackmon over Hilton and Alexander. Blackmon is a big strong reciever that shown last week he can catch in traffic and make plays after the catch. He would make an ideal possession reciever to have with your PPR scoring category as well. For a WR5 not a bad choice.
10 Teams PPR League QB - M. Ryan/ T. Romo RB - D. McFadden/ M. Forte/ B. Brown/ K Moreno/ W. McGahee (Gone)/ C. Benson (Gone) WR - V. Cruz/ P. Harvin/ / G. Jennings/ D. Alexander/ C. Givens TE - A. Gates/ H. Miller/ J. Tamme