Contact Bullseye or Corning
Since you live on the west coast, it might be a good idea to contact Bullseye directly and tell them what you are doing. I know that Genesis makes a 36 x 60 kiln, but you didn’t say you were looking to buy a kiln, just use one. There are several technical questions to deal with on a panel of the size you describe. Since Bullseye brings in artists to work with their glass, and has an architectural division, I’m sure the question has come up for them. If not Bulseye, you might try the Corning Museum. Again, they bring in world-class artists to work within their studio and probably have the technical know-how and knowledge of what kilns are available.
I imagine there are issues of the size of the piece and the thickness of the glass itself that must be addressed when using it in an architectural setting, even if it’s residential. I’m sure Bullseye might be able to address some of those and provide some ideas on how to obtain (through fusing or manufacture) the glass you need.