It will be using Helios for sure both for gauge rendering as well as switch integration. This will most likely be the proving ground for PHCC or Open Cockpit integration.
The entire front panel is scaled at 85% to match the Thrustmaster MFDs (4.25" screen vs 5"). The current render and plan is using two 10.4" for the MFCDS, VVI, ALT, IAS and RWR. Then an 8" panel in the pop out for the ADI and HSI. There will also be a VGA screen in the CDU meaning 5 VGA outputs just for the pit alone. We are still working out how we are going to do the rest of the gauges. We are likely going to do them as steam gauges since the panel configuration would drive us to adding 3 more VGA screens.
Using the 85% scale you could place a single 24" - 27" monitor behind the front panel for all the gauges if you "tuck in" the flaps and fuel gauges to no wider than the outside edges of the MFCD. You would then need to bulk up the lower left panels for the switch backs. We dropped this due to the visuals of the panels with only the two deep panels on the lower left.