G.Skill Ripjaws X 8 GB (2 x 4 GB) DDR3-1600 CL8 Memory (F3-12800CL8D-8GBXM) - PCPartPicker
G.SKILL RIPJAWS X Series 8GB (2x4GB) DDR3 PC3-12800 1600MHz F3-12800CL9D-8GBXL | eBay
G.Skill Ripjaws X Series 16 GB (2 x 8 GB) 240-Pin SDRAM (PC3-12800) DDR3 1600 CL10-10-10-30 1.50V Dual Channel Desktop Memory Model F3-12800CL10D-16GBXL at Amazon.com