I expect this would be fairly difficult to get done as the glass is the real issue. It is tempered and curved and made for a specific use and in a specific size. Having a one off piece of glass made will not be easy. You could have it done in Lexan or Plexiglas plastic I suppose. You will have to find someone who knows how to take the door apart, and once into it, see if the glass somehow fits into the metal frame, or if the frame and window are made in one assembly and then riveted into place in the door. If so, that is going to be another whole level of difficulty to change out.
My overall guess is that this will be a much bigger problem than you think, and will cost far more than is reasonable.
But, then I could be totally out to lunch on my assessment of the scope of the problem to do the job.
I would love to have clear (non tinted) glass in my new AS, but unfortunately it is not available from AS either as an option or a change out. You can only get tinted glass, like it or not. Many cars are the same, only tinted glass is available and is standard, with no other options no matter what you want.