UGREEN NAS DXP2800 2-Bay Desktop Network Attached Storage, Intel N100 Quad-Core CPU, 8GB DDR5 RAM, 2.5GbE, 2X M.2 NVMe Slots, 4K HDMI, Ideal for Content Creators and Enthusiasts (Diskless)

If you want an AIO system you can always get the step up from what I linked https://www.amazon.com/UGREEN-DXP2800-Quad-core-Attached-Diskless/dp/B0D22HBFK1?th=1 This should be able to run Plex as well as being able to support transcoding. I'm worried how that's all going to survive in a cupboard, noise, cooling, boot up and down. I'd suggest not having the NAS in a cupboard in a condensed space (it's a computer). If I need a pc, do I need a nas? can I just get docks for old laptop hard drives? You can do whatever you need to lol. My original suggestion leaves you with more options down the road. I have my PC hooked up to my TV as a server, it's pointed at the NAS for storage and storage only. We turn everything except the router off at bedtime The ugreen NAS has a scheduling feature so it can turn itself on and off.