For something you want to keep running for months, I’d focus less on the initial setup and more on maintenance. Keep regular backups, avoid changing several things at once, document your configuration, and leave some headroom for storage and memory.
For Minecraft specifically, I also like keeping the client side simple and stable rather than constantly adding mods. If you want to play Minecraft Java on Android without paying for the launcher, you can also check out Minecraft FCL free as an option. The main thing is having a setup you can easily reproduce if something breaks later.