In the end, I decided to go with a door based on Rupture Farms. The door i'm planning to create is the door to the Board Room (just before the countdown at the end of the game (screenie here)).

I thought the Board Room should have been a bit more intimidating and different from the regular Zulag doors in the farm (factory :P).
Here, I have jotted down some notes to show what I plan to do, hopefully, to complete the door itself and bring it to life.

Aaaaaaand the logo. This is the actual logo for Rupture Farms. All I have done was colour over the text and re-typed 'Board Room' in the font it uses (Square slabserif 711 Bold).