Welcome to the Forum Christian hope that we can meet up someday.

As far as dimensions I just started building and just guesstimated based on how much room the seat would take above the main spar and simulating that while sitting there and measuring head room. I measured a couple piper Cherokees to get in the ball park.   The plexiglass windshields are from piper Cherokee windshields that I trimmed to fit.  The side windows are Lexan that I purchased from a RV company that builds sky lights for motor homes and trailers.  I got the most shallow dome bigger than the door window opening and just trimmed it the size I needed.  The rear windows are just flat tinted plexi that I riveted in place.  

Also when I built my canopy I sloped it back so the rear door edge opening is sloped back slightly.  That made the windshields fit better and also made the canopy slightly more streamlined by laying the windshields back some.  Also I changed the shape of the rear windows.  They resemble the Cirrus windows.  My door hinges are internal so they don’t show from the outside.  I bet my doors are heavier than the factory ones but I have never compared.   My dash top is aluminum.032. It goes from the dash to the firewall.   

Here are some photos I found on my computer from the build.  Note this is when I still had a Subaru engine mounted to it.  I changed my mind shortly after these photos were taken.  Ill get more photos in a day or two.

After I was complete with  the structure of the door I made a smooth skin to line the inside of the door.  then I covered it with fabric.  You will see in fucture pics.