I like the idea, especially the external antenna, but that only comes with the $85 RaZberry 7 Pro. Total cost $45 + $85 + shipping + tax.
I recently accomplished the same with an $8 (eBay) WS-AP3825i access point and a $26 (Amazon Warehouse) Atrim 800 series Z-Wave USB adapter. Costs include tax and shipping in the US. The AP is larger than your enclosure, but it’s designed to mount on a wall/ceiling with the Ethernet cable tucked behind. It also has rubber feet if you want to sit on a shelf. The AP has 5 status LEDs (3 are bicolor) and dual Gigabit POE ports. For me it was a no-brainer because it was already mounted and in use for Wi-Fi. I just plugged in the USB radio which is hardly noticeable parallel to the ceiling. Yes, I had to flash OpenWrt and shop for bargains on the hardware.