What are you looking at, x299 or x399?

From a budget perspective the AMD X399 seems to be the way to go.  However there are some interesting "quirks" from what I understand that is kind of a result from how they produced the thread ripper architecture.  For one, the "quad" channel RAM is really two dual channels and with some fancy interlink stuff. It works as Quad channel but with a bit more latency than Intel's Quad channel.  Whether that will affect what you do or not would be something you would have to look into.  Not saying X399 is a bad platform by any means but there are some architectural considerations.  The way I look at X399 is that it's sort of a dual CPU system but one physical chip.  Granted that's my understanding from what I have read about the X399 Threadripper platform.  While Intel is more expensive they seem to have a more unified architecture for their CPUs but they lock you into pricing brackets for PCIe lanes, cores, and now apparently RAID features.  At least with X399 you are getting two CPUs with 32 PCIe lanes each.

If you do go the Intel X299 route I would suggest looking at their Xeon offerings.  Both X79 and X99 had a few E5-16XX Xeon variants that were unlocked and overclockable but were not gimped on PCIe lanes or other more professional features but that is something you would have to look up for X299.