Personally, I'd look for the optional sports seats out of
1996 Explorer. I had one, and they were the best OEM seats I
have ever owned. The seats in my 1997 Expedition XLT were
horrid. In fact, they were so bad, I replaced the driver's
seat with a Recaro Orthoped seat. You might consider this
option if your back is really bad. The Recaro seat was very
firm, but that is what you need for a bad back. I had mine
done in material that matched the OEM cloth. I now have a
2003 Expedition and the seats are much better than the 1997
Expedition, but not as good as the 1996 Explorer sport
seats.

Regards,

Ed White