To edit our lengthy feature film (shot in 5K RED and editing on a 4K timeline) we've found we need to abandon Apple and invest in a new HP Z840 Microsoft Windows Workstation.
We’re going to start with ONE (1) NVIDIA Quadro M6000 graphics card, and add another if we find it’s needed. But beyond that, since the price is basically the same for EITHER of the two systems configured below, is it best to go with more RAM – or more CORES? Which of the below will give us more bang for our buck working in 5K Premiere (without proxies), AE, and Resolve?:
DUAL - Intel® Xeon E5-2699v3 2.3 2133 18-Core w/256GB RAM – 1CPU Load Reduced Registered RAM
DUAL - Intel® Xeon E5-2687Wv3 3.1 2133 10-Core w/512GB – 2CPU Load Reduced Registered RAM
For the specific choice you give, it's a no-brainer - the dual 2687w v3 choice all the way. I'd even choose the dual 2687w option over a single 2699 if both had 256GB of RAM. I personally don't run Resolve, but understand that is loves lots of GPU fire-power. You don't mention a thing about drives, so don't forget about them - think lots of SSDs.
With the exception of Eric Bowen, I don't think that this forum user base will know about RED 5k and Resolve. However, the users that frequent the reduser.net forum (post-production hardware sub-group) do, so I would suggest that you post a question of what hardware spec. would be best.
Finally, the link below lists the hardware that was used to edit Gone Girl which was shot as 6K and edited as 5k using a fully Adobe workflow: