Decent specs for your workflow. Rendering times won't be slow with the 5820K, and the Quadro will be especially useful for your V-Ray renders. My only bit of advice is that the GPU is designed for 3D rendering exclusively -- nothing else. If you play video games or if your workflow involves the use of game engines, you'd be better off with a gaming-oriented GPU. Also, if you are planning on using the rig for 3D modelling exclusively, I'd look into a Xeon processor as oppose to a generic consumer one. The E5-2620V3 comes in at a similar price, and will be much better suited for rendering. Otherwise, your build is perfect.
Just to summarize:
3D modelling exclusively: Xeon + Quadro
3D modelling involving game engines: GTX-XXX + i7
PS: I've heard that Quadro cards make quite a bit of noise, so you may want to consider a silent case with noise-dampening material if that's something that may bother you