I would agree with armand, having used an xps 15 for the last few years. Assuming you will use it with an external monitor for critical color work, I would skip the 4k screen in favor of the 1080p, better performance and battery life.
Realistically I think there is only one option, the XPS 15, probably max specs.
AlienWare is Dell and AlienWare notebooks are better spec'd than any XPS
I'll second this. I have the 9570 with the i9 and 32gigs or ram. It's a great machine and i connect it to an NEC for colour critical work. Battery life is okay if you manage it, but I always need to charge it during a long day of photography.