I’m making a camper conversion and putting in a skylight. I want to make a simple roof rack that is tall enough to provide clearance for the skylight. I will make the cross bars out of wood or steel. What I need is some sort of footing... is there a way I can buy just a set of footings that will fit into the rails that are designed in a way that I can then attach a vertical piece of wood or metal to? The stock set don’t seem designed in a way I could do that... My search’s have found nothing. Is “footing” the proper term? I attached a pic of the stock footings. Thanks!