DDR3 RAM Upgrade ?

[Whitcomb]

Hello,
i'm thinking about upgrading my RAM, because i personally reached higher standards in terms of rendering, gaming, emulation, mod's and so on.
Currently i'm using a 8077 MB (Corsair DDR3-1333 DDR3 SDRAM).

Details:

Spoiler: (Show Spoiler)

DIMM3: Corsair XMS3 CMX8GX3M2A1600C9              4 GB DDR3-1333 DDR3 SDRAM  (9-9-9-24 @ 666 MHz)  (8-8-8-22 @ 592 MHz)  (7-7-7-19 @ 518 MHz)  (6-6-6-16 @ 444 MHz)
     DIMM4: Corsair XMS3 CMX8GX3M2A1600C9              4 GB DDR3-1333 DDR3 SDRAM  (9-9-9-24 @ 666 MHz)  (8-8-8-22 @ 592 MHz)  (7-7-7-19 @ 518 MHz)  (6-6-6-16 @ 444 MHz)

I don't want to overclock and i thought about going up to 16GB RAM.
It would be very nice if you could recommend something to me.

System info:
QuadCore Intel Core i5-3570K, 3600 MHz (36 x 100)
ASRock Z77 Extreme4  

best regards

Whitcomb