sudo apt-get install gnupg(this seems to be installed out-of-the-box on Ubuntu)
- Do not install any Java environment but let this be handled by the normal dependency management
The system is currently in light use (still in testing) for my newly founded company and runs quite well. The VM is hosted on ESXi 6 that runs on a Celeron 3900 (yes, two cores) and for a single user with just a few documents stored the performance is really nice.
I so far intend to stay with that system and will keep you updated.