A momentous and productive day! Last night, I researched the dimensions of all the avionics I plan to install, just to verify the suitiblility of their locations in the panel. I'm glad I did this, because I soon realized that if I placed my radios and transponder where I'd originally planned, it would severely limit my ability to mount items on the avionics access door. The Garmin 430W GPS/nav/comm, SL-30 nav/com, and GTX-330 transponder are very deep units. These will have to go on one side of the panel, not separated like I'd planned. The audio panel is a much shallower unit, and will fit on the right side of the panel while still leaving plenty of room for the electrical buses behind. Photo 1: Two of the buses, pushed far to the right on the access door to make room for the avionics stack. Photo 2: An improved layout, with the Schottky diode positioned above the buses. [Entire design later superseded.]