I just got my '63 LeSabre wagon out of the shop. It had a driveline rebuild and a few upgrades. It originally came with a bench seat which wasn't very comfortable and certainly wasn't very cool. So I found an Impala supply house that sells new bucket seat frames and I bought a pair of them for a '66 Impala. I also added a Wildcat console that I found on eBay. The Impala buckets look great and are very comfortable.
That's a good idea. Did they just bolt in or did you have to tweak the feet to get them to sit straight? I would think the floor pans are not identical between the two cars.
Floor pans are going to be the same contour, but its unlikely theres any provision for the inside bucket tracks in the pan (reinforcement/welded nuts).