The advice in the link is pretty spot-on. I agree with all of it. Please also note what they say about 4K: avoid getting a combination of higher-end CPU and high-DPI 3K/4K screen. A 4K screen on a 17inch laptop is not worth it. You can still run 4K if you connect an external display if you really want to. But laptops still aren’t built for that many pixels, due to their cooling systems.
Another piece of advice would be to look at these laptops. While Dell and other well-known brands sell good quality machines, you still pay for design and name. Spend your money on better hardware instead. I bought one around two years ago and it has hardly ever let me down (apart from the NVIDIA Optimus stuff, which is horrible).
Finally: I would advice against the Quadro series, because it is designed for high memory bandwidth, not high shader performance. Quadro is a good choice if you want to drive 16 monitors from one machine, or display a 3D mesh containing millions of vertices. For gaming and real-time graphics, stick to the GeForce series. Also note that AMD is going to release their new GPU in Q2 of 2017. You might want to wait for that.