I have a 54 panel and used heat shield insulation material on the roof and side walls. I liked the roof ribs and decided that whatever I was going to put up as a headliner would fit between the ribs and fasten to the rib flanges. This may sound weird but I used thin gauge gavalume sheet metal (like galvanized steel but with some aluminum in it for a nicer finish) I cut stiff paper templates and then cut out the sheet metal with hand shears and pop rivited it in place one panel at a time. I also used this material on the door panels and side walls. It is a different look and rather impressive when you realize that it is steel. If anyone wants a picture I will try to figure out how to post pictures (I'm an idiot with technology).

All the best, Ted