As a general rule, I'd recommend having a GPU of the same calibre and age as your CPU. And given your needs, this may well suit you.
I'm not an expert in all this graphical stuff, but AFAIK most modellers (inc SketchUp) tend to need to do linear calculations and thus are usually restricted to a single core, so the speed of an individual core is key - so get a good CPU.
Whereas renderers like VRay usually use CUDA on the GPU, so perhaps you should prioritise your GPU? VRay and some other renderers can supplement/help their GPU using the CPU, so spare CPU cores may be useful.
So in short, get the best CPU & GPU there is!
A bit impractical if you are budget-limited? Of course, so have 3 options:
- Prioritise Modelling (CPU)
- Prioritise Rendering (GPU)
- Or hedge your bets with a balanced config - comparable CPU & GPU.
So which do you do most of?
Back to your sample configs, it is worth noting that the performance gap between the i7 6700HQ and the 8750H is approx 40% (based on user benchmarks). The gap between the 1050 and the 180 however is about 250%. If you want to adopt my balanced recommendation, you'd pair the 6700HQ with a GTX1060 or better.