When we took delivery of ours Sling kits, PGC made up a couple of mock instrument panels from MDF to give us some indication of the space available for all the gizmos. Since we've had our EFIS systems I've wanted to see them come to life so I spent a few hours today mounting the basic components of the systems to the mock panel and wired up a 7.5Ah battery.
Primary EFIS is MGL utilising two, 10.4", Challenger screens and a Dynon D6 as the secondary EFIS.
Lots of screen design & adjustments will be required but it's good just to see it alive at this stage.