Which download is the one that applies to the Offline PC? I'm asking because I want to know if the .deb file for the Offline PC includes all needed dependencies. I plan to setup an Offline PC with the latest Ubuntu 18 LTS. Therefore, it would be helpful to know which download is the correct one to setup an Offline PC. Any help will be greatly appreciated.
I do not know from the top of my head, but...
what you need to know (IIUC) is which version of the GCC compiler comes with Ubuntu 18 LTS. If it's a version < 7.2, you want the first Armory package. If 18 LTS has a GCC version >= 7.2, it's the second Armory package.
the consequences of being wrong are perfectly ok, your Ubuntu package manager will tell you "I haven't got GCC version 7.2". It seems very unlikely that 18 LTS has GCC <4.9, version 4.9 is pretty old