New
#11
2x4GB RAM is plenty HyperX Black 8GB (2 x 4GB) 240-Pin DDR3 SDRAM DDR3 1600 (PC3 12800) Desktop Memory Model KHX16C9B1BK2/8X - Newegg.com
You will need 2 or 4 stick of RAM, to have 12GB you would have only 3 sticks.
4x8GB RAM sets are very expensive.
http://www.newegg.com/Product/Produc...=-1&isNodeId=1
Here are several Z77 board to choose from. Newegg.com - Computer Hardware, Motherboards, Intel Motherboards, Intel 7 Series