Gigabyte Motherboard Compatibility

I know the DDR3-1866 2x4 GB recommended RAM for my Gigabyte 990FXA-UD3 motherboard is the CMZ8GX3M2A1866C9. I'm looking at 16 GB for editing as I'm maxing out with 8 GB. What would be the best choice for compatibility with my motherboard?





- 2x8 GB Dual Channel (CMZ16GX3M2A1866C9)



- 4x4 GB Quad Channel (CMZ16GX3M4X1866C9)



- or add another set of recommended CMZ8GX3M2A1866C9 (2x4 GB Dual Channel)





Any help would be greatly appreciated!