@JDCustard You would have to model the IBUS display box, the relevant buttons etc. like anything else. You would then have to script the functions yourself, by basing it roughly on the previous script used by AD156. Else, you could contact Rhys, for the one used in his buses, or AD156 for the Gemini2. Although I have been in contact with both, with Rhys rejecting me due to the London Addon, which is his main priority, and AD156 suggesting I use the existing scripts and model one myself. Although the latter you would have to establish contact yourself.
If I was you, right now I would focus on getting a model, and a bus finished first, and add this in at a later date.