According to ASUS this MB supports 4 x DIMM, Max. 16 GB, DDR3 2000(O.C.)/1333/1066 ECC,Non-ECC,Un-buffered Memory, Dual Channel memory architecture.
So, it's a standard dual channel setup with support for 2000 MHz ram, but not 1600 MHz rm, which is unusual, but not unheard of. A good memory kit for this would be:
Mushkin Enhanced Blackline 8GB (2 x 4GB) 240-Pin DDR3 SDRAM DDR3 2000 (PC3 16000) Desktop Memory Model 996990 http://www.newegg.com/Product/Product.aspx?Item=N82E168...
im planning on buying a used computer to build on. It has a Phenom II X4 970 Black, and the OS is Windows 7 Ultimate. Thanks for all the advice guys, i guess ill just go with 8gb instead of 16 for now.