I am currently using an old laptop (circa 2015) with a 250GB SSD in it, and 4GB of RAM. It runs Fedora 39 Server, and only hosts a Jellyfin instance through Docker right now (though I want to use Nextcloud later too). There is only 15GB of storage left on it, and the CPU is constantly overloaded (due to forced transcoding). I happen to have a lot of 500GB 3.5" HDDs laying around, and I want to use them in RAID 5. What hardware would be good for having 4 HDDs, and running Jellyfin and Nextcloud in Docker? I’m okay with either having just a 4-bay NAS (as long as it can handle transcoding (MKV 480p -> MP4)), or having a 4-bay NAS and a server/computer/NUC. I only have a budget of CAD$900 (USD$658 as of writing), but I am willing to go to CAD$1000 if absolutely necessary.
I use an HP microserver gen 8, which I bought second hand (300$) and upgraded with a better CPU (20$ from ebay) and extra ram (80$) and 4 2TB SSD’s (100$ per). I installed Windows server on it because I just wanted it to work in a way I’m familiar with, but a colleague of mine installed Synology OS on it. You can use the cd drive bay for the OS disk (with some tweaking). Since you already have the disks, this would fit your budget.
I have the gen 10 plus (with an upgraded cpu). I am very happy with that.