I just hate the interface and the small width of the writing window.

You know that you can just edit the notes files with any texteditor you like on any system that is, at least, capable of webdav? I edit my notes with my iphone on the default “notes” app, as example.

You could use also UCS: https://www.univention.com/products/ucs/functions/ At least it can point you in right direction, everything that could make sense is already built in there and there is a free community version

“financially attractive hardware solution”

To be honest. i have a setup at home and my biggest problem are the eletricity costs to run this stuff 24x7. When i compare to a bunch of VPS at some hoster for a couple of bucks a month…

I don’t know what your electricity cost is but keep a eye on energy constumtion of your setup. Whatever concept you want to run, don’t use “old cheap Datacenter stuff”. You will pay a lot in the long run.

Just my 2 cents.