Do you mean you just need a ‘render slave machine’ via V-ray Swarm or you will be using this PC for SketchUp modelling as well?
Considering you’ll need for both modelling and rendering, my recommendation for you:
CPU: AMD Ryzen Threadripper 1950X
GPU: Gigabyte AORUS GeForce® GTX 1080 Ti Xtreme Edition 11G (x4)
RAM: Flare X (for AMD) DDR4 32GB (8GBx4) 3200MHz (F4-3200C14Q-32GFX)
Motherboard: MSI X399 GAMING PRO CARBON AC
SSD: Samsung SSD 960 PRO NVMe M.2 2TB
Note 1: Make sure your memory card (RAM) is Samsung B-die.
Note 2: Consider buying a good PSU (power supply) to improve stability and lifespan of your parts.
Click this for more information.
SketchUp will only use one processor which means multi-threaded CPUs won’t be beneficial for SketchUp usage. So, higher the clock speed (processor frequency - Ghz) better the performance.
However, rendering softwares (including V-ray) will benefit from muli-threaded CPUs. Also when we consider you’ll use multiple applications at the same time (web browser, media player, image editing software etc.), it’s more sensible to buy a multi-threaded CPU (slight decrease on clock speed will be acceptable).
Sometimes hardware specs and parameters doesn’t make sense, so it’s best to trust benchmarks:
Check this for High End CPUs comparison.
Check this for High End Videocards comparison.
Also take a look at V-ray Benchmark and compare CPU & GPU specs and their ranks. (You’ll notice Xeon CPUs and Quadro GPUs, they’re out of range for your budget. Those for big firms that -money isn’t much issue- require precise graphics display with hardware consistency in the long term.)
Lastly check this article about GPU rendering from V-ray. It will definitely be a better/faster choice for rendering but don’t forget that it’s still being developed and you might tweak parameters differently comparing to CPU rendering.