Ill chime in as well as to the importance of buying kits and go one further to try your best to buy one of the kits that are listed on the approved vendors list for your MOBO.
16GB is usually plenty for gaming although I have had some games that pushed that 16GB to the very edge of saturation. I'm always one to go with as fast as the MOBO can handle with the most capacity. Some will argue that you cant OC but I can prove differently as Im currently running a 6700K at 4.6 GHz 1.375 Vcore, 1.35 Vram with 64GB Gskill Trident 3400 MHz. I actually started with a 32 GB corsair dominator 3400 kit 4x8GB and the machine would not post. Went back and saw it was not on the approved vendor list and sent it back and got the 4x16GB Trident kit that works flawlessly. I go for more because I do a lot of batch photo process and a bit of video editing that uses every bit of the 64GB and screams for 128GB. I've never heard of higher capacity sticks causing undo stress on your memory controller, that's a new one on me and I've been at this a long time. My first PC was before the internet existed and it didnt have an HDD and memory was measured in kB. Either your system is rated for it or it isn't, pretty simple concept.

“Two things are infinite: the universe and human stupidity, I'm not sure about the former” ~ Albert Einstein