I have been thinking about having a roof rack built but I would want it out of aluminum. I like the design of the first photo but I would want it to attach like the trackracks (i.e. bolted into the fiberglass with threaded inserts. I would use 1" round tubing for the sides and 3/4" square tubing for the runners. If you look at the top dimensions of a Gen1 4Runner, something like 42" by 66" would be perfect.