My 2 cents ... I did something similar ... was going to get the Vipers ... and after talking with Space Monkey ( thank you, my friend
) ... I decided to go with the 8Pack and they are amazing.
BUT ... I went with the 8Pack 4500 since there was a really good promo here in Portugal ( i wouldn't pay the full asking price for them of course
).
After tweaking and this was my first time, I was able to get 3733 16-16-16-32. I guess I can do more, but my knowledge is limited and as soon as I start getting too many errors or crashes I simply stop since I don't have the time to spend days tweaking memory.
At the end of the day, what I want to tell you is, get the 3600CL16, turn on the XMP profile and enjoy it. You can even push those to 3733CL16.
I bought the 4500 because I don't know what Zen 3 is bringing so I wanted some higher-spec memory just in case, but the hassle you go through to set those to the speed you want ( or you think you want ) is a hard path ...
... although is really good to learn of course ... if you have the time