Need your help....

Requirements: Stream to no more than two platforms (fB/YouTube) using 3 SDI cameras (PTZ Optics: one 20x ZCAM and two 20x PTZs).

So here's what I'm considering...

Option #1: Sapphire Reference System - Cost ~$2,500
Laptop: Acer Predator Helios 500 Intel Version-i7-8750H/GTX1070/G-Sync/Thunderbolt 3 (PH517-51-72NU)
- Intel Core i7-8750H (6-Core) 2.2 GHz (Turbo up to 4.1 GHz)
- GeForce GTX 1070 8 GB
- 16GB DDR4 2666MHz
Thunderbolt enclosure: Akitio Node
DeckLink Duo 2 (I recently read someone has issues with the PTZ Optics SDI cameras on the Decklink - is a Magewell Pro worth the extra $400?

Option #2: Custom Desktop - Cost ~$3,672 (Or build it myself for ~$3,000)
Desktop: Digital Storm Slade 2
CPU: Intel Core i7-8700K (6-Core) 3.7GHz
Motherboard: ASUS ROG STRIX Z370-E Gaming
RAM: 32GB DDR4 3000MHz
Graphics Card: GeForce GTX 1070 8GB
Capture Card: DeckLink Duo 2

This system will be a dedicated for live streaming. Which would you choose? Would you recommend a different enclosure (APC IO is too pricey considering the cost of an enclosure).

Appreciate any wisdom offered. Thanks!

-Jeff