http://www.classic9leathershop.com/Seat_Reupholstery_Service_and_Kits.html is one that sells kits and may be a place to start. The back of Excellence mag has them and some others advertising kits. But these guys saoud as if they might make em.
Also consider the wrecking yards as it may be easier just to swap the seat if you can find one that matches.
Reminds me I have to make an appointment with my local leather guy to get my wife's Acura seats (in tan) patched..the rip is not all the way through and they say they can patch it so it will be good as new.