Sanity check for first time media server build

I’m currently running my Plex server off of a tower originally built for gaming and media production. When I initially built in 2017, it had a 7th gen i5, 16gb RAM, and a 1080. Rebuilt to modernize at the end of 2023 with an i9, 64gb RAM, new mobo, basically the only thing left was the GPU, PSU, and some drives. We’ve moved to Macs for the production tasks in the past year, and aren’t gaming on it as much anymore, so I’m looking at options for moving Plex to a less powerful, smaller form factor machine that can also host Audiobookshelf/Komga.

I’m torn between wanting to repurpose some of the 2017 hardware in a smaller case and running Unraid, or finding a used Mac to pair with an enclosure for the media drives that are currently in the PC. I’m leaning toward repurposing the hardware since finding the Jonsbo N6. I got a little ahead of myself and ordered a decently priced new old stock micro ATX mobo compatible with the old CPU and RAM, but I’m trying to get a sanity check on if it’s a good idea to rely on nearly 10 year old hardware to run this system. The build would still require me to buy a decent amount of additional components, including the case, a new PSU, CPU cooler, a cache drive, and another large parity drive. I have a buddy willing to sell me a 2021 M1 MacBook Pro for a decent price, but I’d still need some kind of TB drive enclosure, ideally with room to grow, and additional storage in order to back up my existing media before formatting for Mac.

I’m sure the Mac system would likely save me a bit in terms of overall power use, but I’m heavily leaning toward continuing down the Jonsbo path because of the expandability, and the ability to reuse components I already have. I’d love to get some opinions from people with more experience than me on my options.