I've been looking for some better seats for quite some time and just recently picked up a set off of eBay. I got a set of 35th anniversary seats that are black with gray in the middle and the pony is stitched into the seatback. I can't wait to install them because the 13-year old seats just don't cut it anymore. The newer seats Ford puts in the Mustangs are far superior to the crap they used to. Keep an eye on eBay if you're looking for some newer Mustang seats. I see alot of 98 and newer seats advertised there.
Or, if you want some race seats check out Recaro, Cobra, Sparcco or Corbeau.
www.corbeau.com
www.cobraseats.com
I'm not sure about Recaro or Sparcco's web address.
I work with a ricer and I was flipping through one of his magazines about a week ago and noticed that aftermarket seats were advertised on just about every-other page. This is a huge fad amongst ricers so you may want to pick up a ricer-mag to get a good look at some other stuff that's available.