I think the Miata seats can look and feel very good, the only downside I'm aware of, is I've heard guys complain about using their 4 or 5-point harness with them. The Miata seats do not have provisions and cause the shoulder belts to sit very wide or uncomfortable.
Are you interested in looks, comfort, or performance? (hard to get all 3)
If you are interested in performance, I installed Ultrashield Rally Sport Seats in mine and added a little padding. They are comfortable and great for support and neck restraint. (not as goodlooking as I would like, but not bad, also easy to add seat heaters!)
https://www.ultrashieldrace.com/cata...Sport-Seat/160
They also make a Spec Miata seat without the wings, but still has the harness slots.
https://www.ultrashieldrace.com/cata...Miata-Seat/161