Hi Smitty - of course I'm not flying yet so take all of the following for what it's worth. Also, it's your panel in your plane, so make it the way you want!
I'd lift up your EFIS - better to have it so your eyes don't have as far to go between EFIS and window.
As for the mechanical instruments, I don't think you'll need them. You should find that you can transition to tapes pretty quickly, especially in a VFR airplane. If you want them as a backup (because all things fail) then I'd go with a Dynon D6. The reason is that then you have a completely independent EFIS for about the same panel size as your two mechanical instruments. You get a 2nd source of attitude and heading as well as altitude and airspeed.
I'd ditch the key switch - because the dangling keys always wear the paint on the panel.
Ditto on the split master - expensive, and not really needed. You can wire two regular toggle switches to do the same thing (see AeroElectric Connection).
Ditto on the circuit breakers. They cost like $20 each, and they aren't really something that you want to mess with in flight. BTW - they are a royal pain to work on in the plane - because of the tiny screws and the angle that they go in on the back side. I've had enought bad experience with them in the Skipper that I'm going with auto fuses on a shelf that swings down under the right side of the panel. I still have just a couple of CBs on the panel for stuff that I want to cycle in flight(like ALT FIELD because of overvoltage protection). If a fuse blows, I land and figure out the problem on the ground. The FAA just release guidance that resetting breakers in flight isn't a good idea.
The map box is a real pain. It is very deep and requires a lot of subpanel mods. I went all the way through that and then ended up with a dual display panel and removed the map box. A lot of people who have it say it isn't worth it. Certainly personal preference, but putting in the center top of the panel is wasting prime real estate... maybe you could consider moving it over to Vans recommended location?
You'll be using the EMS a lot more than the map box- I recommend that you move the EMS to the center top (aligned with the top of the lifted up EFIS). I can't remember if you are building a TU or a slider, but if it is a slider you don't want to mess with the center rib too much. There is heavy structure there for the roll bar brace. That will effectively limit the vertical position of the EMS. Remember to account for the depth of the boxes behind the panel as the ribs / structure generally descends as you move further forward.
I like the passenger headset jacks on the panel. Passengers seem to change a lot and often come with their own headsets. I put the pilot headsets on the aft end of the arrmrest.... so there would be no wires strewn about in the cockpit when I'm by myself.
I'd leave the hobbs meter (but get the smaller square one for like $25 from Spruce). It is my one concession to "old school" tech - and will probably be the only instrument in my plane that doesn't eventually get changed out!
Great panel overall! Panel work is my favorite part of the project so far!
Good luck,
