I like either of the two young Mariners over both. Nick Franklin -- who plays 2B but is SS eligible as well for this season -- and Brad Miller who actually does play SS. Are either in your FA pool still? I'm guessing Franklin has already been scooped up earlier but there is an outside chance Miller might still be available.
If neither are available, I'd take Peralta over Rollins. Three players on the same team isn't that bad. Especially if you have a few bench players to throw in during Tiger travel days.