If you have open registration you should reduce the account creation rate.

Assuming you don’t want to expose these services directly to the internet (I don’t recommend it) then you want to set up a VPN to connect back to your home network. Wireguard or OpenVPN are the most commonly used. As far as guides that will depend where/how you want to run it.

The cheapest CyberPower/APC that is pure sine wave should be just fine.