I have the battle mats and containers from Infinity, which are nice and work in a pinch. But I wanted something more, something modular and with lots of walkways and stuff.
So I dug around on the internet, looking at buying terrain or building my own. But then I saw Battlesystems (http://www.battlesystems.co.uk/), which is exactly what I want. They even have their second sci-fi pack up on kickstarter (https://www.kickstarter.com/projects/1621774283/battle-systemstm-sci-fi-ii-terrain). But I don't want to wait a whole year to get that kickstarter, and their first sci-fi pack only lets you build so much.
But, paper terrain, that sounds like a viable option. And I believe I found the solution. Stones Edges' Orbital Starter (http://www.stones-edges.com/scifi/orbital). Obviously they designed it to be a spaceship layout. But I see so much more potential. And so I have begun the laborious process of building a modular system out of the basic starter pack.