Even though Howard longed for a Sietz window over the galley space where the poppy quilt had been hanging, he had to face the reality that finding one in the US was not going to happen, and importing one would be hideously expensive. In the end we ordered a window from Motion Windows in Vancouver, Washington.
The windows are made as replacement windows for RVs and trailers, but since the sides of the Promaster are basically flat and straight, we figured a trailer replacement window would work for us.
The one we got is a double pane, slider with a screen. Jeff at Motion Windows was very helpful and answered a million questions for us about ordering the window (custom sizes available) and the instillation. Never the less, when the window came, it sat in the garage for quite a while awaiting a surge of the wild abandon it takes to saw a giant hole in the side of your brand new vehicle.
Now that the window is installed, I like it a lot. It lets lots of light in, along with ventilation. It looks like it was factory installed because the black trim matches the factory windows. I made the same red accordian pleated curtains as I did for the other windows.
So that's the majority of the big (AKA expensive) jobs done. We are thinking we'll probably get a swivel seat base for the passenger seat at some point, and though we've made a canapy from leftover dacron sail fabric to go over the side door, we've never really tested it out in campling conditions, so it might end up blowing away in the first puff of wind. All will be revealed in due time.