Upgrading from 1xR9700 to 2xR9700. Thoughts on build before buying?

A user is planning to upgrade their existing R9700 build with 64GB RAM to a dual R9700 setup. The primary goal is to enhance speed and enable running Qwen3.8-Flash-Next at Q4/higher quants of 3.8 27B. They are seeking feedback on their proposed component list before purchasing the additional parts, which include a second ASRock Creator Radeon AI PRO R9700 32 GB Video Card, a Gigabyte B850 AI TOP ATX AM5 Motherboard, a GameMax MeshBox Pro ATX Mid Tower Case, a be quiet! Power Zone 2 1200 W 80+ Platinum Certified Fully Modular ATX Power Supply, and ARCTIC F12 53 CFM 120 mm Fans.

This post details a specific component list for upgrading from a single R9700 to a dual R9700 setup, unlike general discussions on multi-GPU configurations.