seats

Car seats a re sort of like sofas and chairs in a room. All same but different. So measure the available space then go to the pick and pull with your measurements.
I made the mistake of putting 67 sport fury buckets in a barracuda once. The seat bottom hit the door panel. Had to open the door to access the release lever.
Majority of alternate seats will have their levers under the front of the base.
I saw a nice pair of leather Volvo buckets in a A-body once.
I heard one guy saying he was putting 4 heated buckets in his A-body. He didn't say what vehicle they came from.
Hope this helps