What I have found with my lighting, it is not brightness that helps with my painting, (my shop is very bright with lots of lights from above), but I need reflections of the lighting so I can determine how smooth the paint is going onto the surface. I needed to put up more vertical lighting on the sides and the ends of the car so I can look down a panel and see a light source that I can see a reflection and that helps me see if I need more paint on the surface.
I haven't read the posts on ventilation yet, but what I was thinking was use a window opening with filters for the shop makeup air and then use one of the round turbine fans that connect to 12" hoses. I was going to run the suction inlet hose underneath the car with lots of holes and run the outlet out of the shop. My thinking is, this may make it more like a downdraft booth, move the paint fumes from top of the car to the bottom and then out the fan. The window and filter for the makeup air is toward one end of the booth and the outlet is at the other end.
I have used one of these fans with an outlet just to blow paint fumes out of the shop and it works very well, I haven't used one yet with an inlet hose connected.