HP elitedesk or some other desktop can be had for cheap on eBay second hand. They will make decent servers. Install Ubuntu server or some other Linux flavour. Use docker compose to deploy services. Use tailscale to connect to these as others have suggested. Their docs on how to setup tail scale only ssh are really good. If you feel note adventurous you can get a domain and expose services via subdomains using cloudflare tunnels.
But for your use in suggest tailscale for now. Add some storage into the machine and you are good to go. You can use restic backup to safely backup to a remote location like backblaze b2, another storage on your network, or any other number of options.
That's pretty much it, sounds so simple right? /s It will require some reading but there are usually ready made docker compose files for most projects as well as examples for restic. There are always multiple ways to do this but that's close to what i do and it's worked so far (tm)
And just ask on this community if you get stuck.
The loop hole would be that suddenly declare that he wasn't officially elected because he cheated his way there /s