Buy the G.Skill 8GB (2 x 4GB) DDR3 1333 (PC3 10600) Desktop Memory DIMM (F3-10600CL9D-8GBNT) - Untested | GoodwillFinds
Amazon.com: Timetec 8GB KIT(2x4GB) Compatible for Apple DDR3 1333MHz PC3-10600 for Mac Book Pro (Early/Late 2011 13/15/17 inch), iMac (Mid 2010, Mid/Late 2011 21.5/27 inch), Mac Mini(Mid 2011) RAM Upgrade : Electronics
Timetec Hynix IC 8GB KIT(2x4GB) Compatible for Apple DDR3 1333MHz PC3-10600 for Early/Late 2011 13/15/17 inch MacBook Pro, Mid 2010 Mid/Late 2011 21.5/27 inch iMac, Mid 2011 Mac Mini - Newegg.com