You’ll likely pay big money to have one custom built to vehicle safety standards. I believe those ones are made by Creation windows which no longer are around of course. There are auto glass places and rv places that should be able to figure out what part of the window has failed and perhaps fix it. It may be as simple as one of the gaskets or it may just need to be resealed. If you ask on a PW forum, you’d get more relevant answers from others with the same rig as you.
2006 Pleasure Way Plateau TS