I personally prefer both the function and look of the stock seats. I also like the tumble function of the stock passenger seat, as I still use the rear seat quite a bit. Maybe I'm a hard@$$, but I've driven mine for nearly 8 hours at a time on road trips and I don't get uncomfortable at all in the stock seats, though everyone's results may vary. I tend to think the uncomfortable part comes from the fact you're riding in a 40+ year old vehicle, and no amount of padding is going to make it ride like a Cadillac.
Some people prefer aftermarket seats, but typically that is due to safety reasons (headrest/better seatbelts). The problem you run into with a lot of aftermarket seats is they tend to sit a little high on the raised floorboard of the Bronco, so if you're a taller fellow, you end up staring at the top of the window frame and/or hunching down to see red lights. Some folks have fabricated custom brackets to make them sit down lower, but I believe your options are limited due to the typically thicker nature of other seating options.
