Looking for Good DDR4 RAM

[uSavagePatchKid]

Right now I have 8GB of Crucial Ram @ 2133 Mhz. I found this and I am thinking of buying 2 of them (for a total of 16GB). Should I pay more for 4GB DDR4 @ 2133 Mhz or just mix them. If I did mix them how would it work? Here is my build.

 

[Dark Lord of Tech]

Mixing or Adding memory is hit and miss even if identical. Best purchased in a matching set.