I know many here are explaining the "best thing" for your situation, but I still recommend you take all of this advise with a grain of salt and look at the actual results from others using it. I know the lists are short, but many of us haven't yet had the time with the new platform, and the slowness of anything new in RAM rolling out ATM ( I think so they can show it all off at CES first). What you will find is that 3200-3600MHz kits all perform differently depending on the tasks you want to complete. Most of the advice has been given to achieve the best latency, (which isnt the end all of DDR4 clocking performance for AMD) but most seem to think it is. If you are hunting for the best bandwidth in something like AIDA64 sure, but in real testing outside of that application, things can change at a drop of a hat, no matter how well they do in AIDA.
Patriot's Viper 4 Blackout Edition DDR4-3600 16GB dual-channel RAM is the most affordable 3600MHz CAS17 kit we could find and it's tested here.
www.tweaktown.com
With a polished silver heat spreader and a pastel RGB LED diffuser that is available in seven different colors, the PRISM II RGB kit from V-Color certainly has flair. This premium kit has the perfect sweet spot for Ryzen performance with a 3600 MHz XMP profile and is affordably priced to boot.
www.techpowerup.com
The first link uses your board, and it runs a 3900X so that AIDA results are comparable to Intel system testing, without losing half the write bandwidth, which is what is shown using the 3600X and the MSI MEG in the second. There are plenty of sites now adding AMD DDR4 testing, and likely you may find kits that TweakTown and TPU have not used.
A lot of the advise is solid. Go for good b-die (straight timed...IE 14-14-14), even the new hynix chips. Buy the speed you want, as even what you see in reviews may not be attainable, but the board you chose is designed for RAM tweaking with special attention paid to the layout of the motherboard to aid in that quest. It really comes down to the IMC, and if you want to clock for the stars, opt for the 3600X as it is what is able to run 5000MHz RAM currently.
I know the choices are overwhelming. I say go somewhere like Newegg, select down to maybe 10 kits based on speed, timings, arrange them by cost, and eliminate anything with RGB. You will be left with a very short list of kits to do your homework on.
Sorry it took so long for me to spill my guts, but I have only had short bursts of time to drop a couple pennies here and there.