Since we hope to use the truck in all four seasons we wanted windows that were insulated and had as little cold bridging as possible. After living 22 years on a sailboat, some during the winter in Boston we are familiar with condensation, and really want to avoid it. Another requirement was shades and screens on all windows. The shades will need to be blackout and help keep warmth in. The screens need to be fairly fine for smaller biting insects.
Windows for trucks like this come in 2 basic flavors, plastic and glass. Each one has drawbacks and benefits. Plastic lens windows are way lighter and less expensive and available in the USA. Glass windows are more durable but way heavier, more difficult to install, much more expensive and available in Europe.
We ended up going with Tern Overland for our windows and doors. One of the reasons was the availability in the USA, another important one was cost. Not to mention the weight savings over glass windows. Of course there was a couple of drawbacks. One is that the plastic lenses scratch easier. Another is the cold bridging on the aluminum frames. The only real solution is windows/doors with composite frames, which can be had at a much greater cost. We just needed to keep this build cost down so made the concession. I have to say though that we have been in 5f degree weather with the Webasto hydronic furnace purring away and the condensation is manageable. Just a quick wipe in the morning, then crack a window and all is good!