For me, finding this upholstery has been like finding Elvis in my backyard!
My only advice is try and find a good junkyard. Cloth and leather upholstery are definitely some of the hardest items to find after 10 years. Manufacturers have no interest in stocking this stuff because it sells so slowly and takes up inventory space.
You can check sites like car-part.com. Though some of these yards can be pricey. Because of the number of variations and colors, it's a lot like looking for optional equipment (the luggage rack, bass-boost audio package, special Oldsmobile wheels, etc). The good news is, if you have bucket seats, in many cases the cloth on each side is interchangeable. So find a nice passenger seat, and switch out the fabric and padding on your beat up driver's seat.
You might want to check the white vehicle code label on the inside of your trunk to determine what the RPO code is for your fabric. We have a great list here on the forum:
http://www.gmwbody.com/forum/faq/gm-rpo-codes/ If you happen to find an 82D passenger seat (gray with black stripe cover power seat) from a Cutlass International, let me know bro!