Go for the 4K Samsung, it is a great monitor. The 144hz monitor is only 1080p.
Your 1070 Laptop should run about 20% slower than a regular 1070. In my experience, a regular 1070 does 4k at 30-40fps on almost all AAA games at Ultra. If you turn down settings a bit, you should certainly be able to get 30fps at 4K on your laptop. You could also consider lowering the resolution to 1440p or something like 1800p, and you would still get great performance and image quality.
I wouldn't get that 1080p 144hz monitor, you can get cheaper 144hz 1080p monitors when there aren't even sales on, that's not a deal, but that 4K is an awesome deal.