After a few hiccups getting the right MB/CPU combo to work, I can now say I have a new working Ryzen based Linux server. It has been running for a little over 24 hours now and performing like a champ.
Very happy with the MSI motherboard, and running the OS from the NVMe SSD is amazingly fast. I ended up removing all other media before installing Ubuntu Server 17.04. The installation media found my Samsung EVO without any issues and boots up fast!
Once I had the system up and running, I attached the secondary 1TB drive to store system backups and non-IO critical files.
I think you can get significantly more power for your money if you go the route of putting the system together yourself. I am not a gamer so I did not need any fancy graphics card. The system runs headless for the most part anyway.
Also, I had to order the Noctua AM4 adapter kit (around $8) in order to use the NH-D9L fan, but it was pretty simple to make the adjustments to make this fan work with this CPU/MB combo.