What's SS/DS/v/2pcs in Memory Support List?

Here are the meanings and explanations:

DS = Double Sided (RAM chips on both sides of the PCB)

I hope that answers your question satisfactorily.

As for the 2 kits you are asking about I would say the Kingston kit you listed first should work without issue but the second is uncertain. Just because a lower capacity version of a kit is listed as supported does not mean the higher capacity one will be. In many cases the higher capacity kit may use different timings or higher voltage or even different memory chips. Even if an 8gb version is listed as supported there is no guarantee the 16gb version will be.  

That is not to say that just because a RAM kit isn't listed in the memory support list that it will not work. The memory support list is created at the time of product release and is very seldom actually updated. It is difficult for a motherboard manufacturer to procure and test every new memory module that hits the market. In contrast, it is very easy for a RAM manufacturer to have a collection of motherboards and test their own products on them. Generally speaking if RAM works on one ASRock Z170 motherboard, for example, it will most likely work on all of ASRock Z170 boards unless there is some drastic difference (like an ITX version may have different support). This means that most often the RAM's product page will have a more comprehensive list of supported motherboards than supported RAM modules on the motherboard's support list.

We have seen a lot of problems here on the forums with people trying to mix and match 2 dual kits. The Skylake platform seems to be very picky when it comes to using 4 RAM modules. All that said I would go with 2 of the Kingston KVR 32gb (2x16) kits as it would seem that it has been tested with the board in that configuration.