I've always used Honda seats for the most part. Lightweight, low profile, and the leather ones from Preludes are sweet......plus I know a guy that owns a Honda specialty service center and he gives me good deals on seats out of his parts cars. They are far from bolt in though. The mustang seats are pretty common, and easy to do, as beretta pointed out. I'm going to try some C4 Corvette seats in the CJ when I find another set for a good price. There are all kinds of seats in the junkyard, and the possibilities are endless if you can make some adapter plates. Just a flat plate on both sides of the seat with both bolt hole patterns is enough if the span isn't too large. I used a modified rear bench seat out of a Chevy Astro van in the front of an 81 CJ7 one time.