I added the Pro Xover Cottage last year. Shorter rods only in there but I like it a lot. Since you have the pro seat and the black plastic base the seat sits on already all you should need is the cross rail, rail brackets and a couple of end caps. Looks like the rail and caps are available on Otter's website under replacement shelter parts. Might want to email or call them about the brackets. Previously I fished off of a Magnum Pro sled with the seat rail and pro seat without the canvas. It was easy to add the seating and quite comfortable. Good luck