Personally I find 16gb is more than enough for all the games you could possibly play, though if you want to go to the maximum, then follow me.. I have all the things for your nefarious needs..
Alright so basically the rule as I know it is the ram modules need to be low voltage due to the CPU we use, which is what you've linked. However you don't need performance ram tossed into the rig with the other three common sticks.
You can easily look at what you've got in your system by taking the back panel off and taking a peek at the module. OR you can go here:
https://www.piriform.com/speccy And download Speccy to identify what the ram is.
Here's what I've got:
Type DDR3
Size 8192 MBytes
Manufacturer Hyundai Electronics
Max Bandwidth PC3-12800 (800 MHz)
Part Number HMT41GS6AFR8A-PB
Serial Number 1369A70D
Week/year 38 / 13
Basically what you see similar to this (when you click the slot dropdown button under the RAM section) you'll be able to identify what you've got.
You don't STRICTLY need to match the modules, but I prefer to do so as I believe in manufacture matching.. kind of like using the same make batteries in the TV remote.
Your ram won't die anytime soon either, so you don't need to fork out the extra cash for extreme RAM modules like the HyperX.
❤