IN doing my own research, here is what I have found:
1. If your seats are shot, Katzkin will be your best bet. The seats SHOULD (i repeat, SHOULD) be the same from Gen 1 to Gen 2...the only difference is the upholstery pattern itself. That said, I have never taken one apart.
2. This is for SHO owners who still have seats in cracked, but good condition: YOU NEED TO FIX THE SEATS NOW, before they get worn out. I have called around to various leather repair places, as my seats are cracked but otherwise intact. The cost to refinish and reinforce the seat from a local Ferrari and Maserati leather tech: $150 a seat.
Call me crazy, but that sounds like an insane deal to me. He will sand down, fill cracks, color match the finish, and then respray the seats.
Here is the man I intend to use, when the time comes:
http://www.technique-leather-repair.com/
Here's what I am working with....he says they are "very restorable, to near 100% condition":