In an attempt to get back to the topic - for that big open 6'x8' space that the OP has, the layout that SMK used would work. As I recall, he bolted 2 big panels together by the long sides and laid them onto (3?) pieces of square aluminum tubing. The panels are bolted to the tubing, and ends of the tubing are anchored to the roof. Don't remember if he posted this picture in Members Installs thread.
PS:
found it. Not clearly visible, but looks like there are 2 pieces of tubing under that two-panel combo, going across the "joint".