Prefaced with the fact i don't know what your building, what you want to use it for, and how long you think before you compete it.... but a few observations:
Id leave any avionics decisions to the absolute latest possible point in the project. They technology is changing so rapidly, that I'm sure that by the time you have the FWF etc all done, the available avionics will have changed significantly. Dynon will probably have a remote radio to match the remote Mode S Xpdr for example. That will make it a lot more user friendly than the micro panel mounts.
Id only consider those if panel real-estate was extremely limited, or you have the fingers of a 5yr old.
As far as the mechanical backup ASI/ALT/Compass. IMHO, thats just a lot of extra weight unless you are planning to fly IFR - in which case the EFIS will be backing up the steam gauges.
The 2 greatest things about modern EFIS these days is that they are infinitely more reliable than their mechanical equivalents, and weigh a LOT less.
Cheers