If you prefer something quiet, keyboards with red silent switches are often available in pre-built options

Buy a second-hand one and you can always purchase new keycaps for a fresh feeling, but 25€ will be a tight budget anyway

I also recommand Task.org app to sync tasks with CalDAV and I use raw Markdown files with WebDAV, both using the DAVx5 app for synchronization. For editing Markdown, I prefer minimalist apps that suit my needs. Right now, I find SimpleMarkdown (with disabled telemetry) to be the best choice.