If it is for home use, why not go with a raspberry pi (or similar, there are lots of cheaper alternatives like it) which is only accessible from the local network and not from the internet?
If access through the internet is needed, you can use one of many free dyndns services. (e.g duckdns.org)
You could also look into existing projects and maybe contribute instead of building from scratch, but thats up to you. Through a quick search I found https://github.com/FSchiltz/Helse
Thank you very much for pointing this out.
I completely forgot to mention this, since I've been running compute modules with nvme's for ages.
Just to add a further alternative: The pine64 soquartz baseboards are also compatible with rpi compute modules.
Also for extra saving: by the time you buy all that, there are a lot of second hand office mini PCs that are considerably cheaper on ebay.