OWC 8 GB (2 X 4GB) ram PC8500 DDR3 1066MHz sodimm 204-pin Memory Upgrade Kit, (OWC8566DDR3S8GP), Compatible with MacBook Pro, MacBook, Mac Mini and iMac at Amazon.com
Kingston 4GB 1600MHz SODIMM DDR3 1600 Memory Module for HP (PC3 12800) KTH-X3C/4G at Amazon.com