I'm somewhat picky on my seats and man do I hate the JK seat!
As mentioned above, some of the quality suspension style seats are Mastercraft, PRP, Beard, etc. I personally have Mastercrafts in my TJ and love them but I wouldn't choose them for a long-distance overland vehicle. Regular seatbelts do not always play well with these seats due to the deep side bolsters. You can run harnesses which is fine for crawling and occasional driving (I run 5 point Crow Harnesses) but that gets old quick when you are in and out of the vehicle a lot.
I'd look into regular replacement buckets. With some research and potentially a little bit of fab work you could easily swap in more comfortable seats from another vehicle. I swapped WJ seats into my XJ and absolutely love them. I am sure they would require a good bit of work to get them into a JK, though.