With regards to the roof vents, they are 6-inch Ventair units.
I liked these because they fit onto one of the wide roof sections, the install is simple. The unit themself is a metal body, powder, or enamel-coated and not likely to degrade with sun like some plastics do. I installed them onto a double plywood backer and used glazing butyl non- setting putty. The foam gasket that comes with it is no use so I replaced it with a better rubber adhesive seal strip.
The fan it appears is directional, it is not a standard blade type but blades mounted on a disc, I think this stops them being efficient in the reverse direction, I did have them wired to a DPDT switch and it might have worked but it was not as I had hoped so reverted back to a single direction, suck. I am looking at changing over to a blade style and adding a variable speed controller.
We mostly use them as passive vents, they can be left open in rain, except if it is driving horizontally and with the smoked caps it is no problem with light escaping of the early morning sun. I paid $50 each for mine via ships chandler - online.
As for window coverings, my wife made up covers for the front two side, sliding and rear windows along with 2 tubular ones and infill for the front window, we bought a custom made front one that is both reflective and black.
We have since changed our operation by leaving the rear on all the time and over-cladding with plywood.
The covers are made with grey felt- Walmart and teh reflective/bubble wrap we used for all the insulation, it is like Reflectix but thicker. Works great.
I have attached a picture of the one that infills around the mirror so you can see both sides and teh construction.