There was a guy around a few years ago that had racks on his A Frame. They were mounted on the sides of the front roof section and the towers were high enough the bars were clear of the bubble window. He was pleased with the situation. That is about all I can tell you.
A kayak on the camper has some drawbacks.
Once you are in camp, you have to have another vehicle to move it more than a short distance. Also I would be concerned about putting a heavy Hobie kayak over the front of the already heavy tongue of the A122S. (Mine has a 20% tongue to gross distribution) This is not to say it isn't safe, because I don't know that. Make sure your TV can handle it.
2012 Rockwood A122S
2008 Toyota Tundra Double Cab 4X4
Former owner of a 2002 Coleman Niagara GTE