We have a Jon boat and were looking for some kind of comfortable seats to put on the benches. We found these folding swivel seats at Cabela's and found they work great. We bought the low back version, but if you plan to fish for hours on end, you might want to get a higher back. The lower back is comfortable, but not for more than about an hour.
These seats are heavy enough that they will not blow away while you are not using them, but still light enough that they are easy to move and lift. The clamp does a great job of holding the seat on the bench, but it still slides side to side and will tip backward if you lean too far back.
The fabric is very durable and has not faded in all the time we have used it. It does swivel 360 degrees, but not as easily as you would think it should. It is much more comfortable than the bench seats of the boat though.