Are both sides controllable?
I think there are two general directions you could go, stylistically:
- Go pure Tron:Legacy shiny sci-fi to contrast with the low- people you'll be managing in the tech people beginning.
- Combine the low and high-tech sides so you have a mix of high- and low-tech in the HUD styling itself.
How to set it up depends on what the gameplay focus is... but since your project is kind of several games in one, I would lean towards really minimalist decorative parts so you won't have to modify them as much. Start with dark polygons to write text over then add pretty frames as necessary.
Here's what I came up with for a hybrid-type HUD: