Hi, Im in the same situation as you, I´m an architect and have just built a medium render and cad use sff pc. In my case it´s a gigabyte x570 board with a 3700x and 16 gb of RAM. If you have any questions just ask me, I only have this working since sunday so it´s quite new for me but I´m working my way to make it work properly.
I still haven´t bought a graphics card, so I´m using my olt gtx 960, but normally nvidia works better with the programs I use (lumion, sketchup)
As for RAM I have a couple of 8 gb stiks 1 rank crucial ballistix 3000 cl15 that I´ve made work at 3526 mhz 14-17-14 at 1.5v set at BIOS. it´s not a definitive setting as I´m still investigating. This ram cost me just 90 euros, search for "AES" at the end of the serial number so you get the micron e die chips, in case you are interested.
I can tell you also that Im suprised to say the least as tyo how these ryzen chips use voltage... Working with autocad, the thing was all the time at 1.47v and near 60 degrees with the noctua 12cm slim blowing at a scythe shuriken rev B... when rendering it throttled until 3800 mhz or so... Now I have to settings stable one of them 1.25 and 4.000 mhz and the other 1.35 and 4.150 mhz I like the first one better and temperatures are way cooler this way because it nevers gets to 1.47 v while doing light workloads... although maybe you wont have this problem if you are going to use an AIO... anyway its something to take in mind, and I hope they improve how this works over time.
One last thing, the fan on the gigabyte is not a problem noise wise, I have a noctua 12x15 fan at 940 rpm at idle and with the noise of that one I almost cant hear the tiny board fan... its noise characteristic is a bit more on the "high pitch" side so you can discern the noise of one fan over the other, but it´s not problematic at all.
