OEM leather seats. I went to OEM when looking for new leather covers for a 2001 Miata I bought in 2009. Was quoted 1,100$ each side plus installation so I investigated after market and found leatherseats.com which offered what I was looking for at 890$ a pair (all Cdn $$). This company also supports DYI installation and sells a kit including pliers/hog rings. The surprise was the discovery on doing the install that the supplied materials were higher quality that what Mazda provided. Went with this company only because at the time other suppliers would void warranty if NOT installed professionally. I am not suggesting that this was the best quality and/or least expensive product available, only that it best met my needs.
Installation was scary for me. But the process was suggested by an installer who felt this approach would be waaaay cheaper than having him make and install new leather in-house. He agreed to be fall-back in the event I needed to bail, and would do the install for 550$. These seats still look great and are wearing well - actually don't look like they're wearing at all. But then the car is in storage all winter.
Brian