Help upgrading RAM - mixing 4gb with another 4gb different cas

Hi,

I want to buy some more RAM for my computer. I have now 2x4Gb of this one:
http://www.overclockersclub.com/reviews/samsung_green_ddr3l/2.htm

Which is a CL11 (11-11-11-28) @ 1600MHz (PC3-12800)
That one is no longer on the market, so I am looking for the cheapest/best 2x4Gb to add to the system.

The Motherboard is this one:
GA-Z77-D3H
http://www.gigabyte.com/products/product-page.aspx?pid=4140#na

This is the memory list:
http://download.gigabyte.us/FileList/Memory/mb_memory_ga-z77-d3h.pdf

So more than 1600Mhz is not worth it it seems.

I found several options but I am not sure if I must look for CL11 or if I could pick CL9 or a different one.

I would like to OC this machine in the future (and the RAM I have is good for that I think).
Maybe I could buy a better one and OC the actual RAM to match...

Any ideas?

Thank you!

Find matching timings and voltage or sell what you have and buy all new is my suggestion.

The only kits based on Samsung IC right now are G.Skill TridentX and that memory should work with your kit but probably better will be to sell it and get 2x8GB.