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.