The standard bench seat in a Seven is in my opinion (I know, not in many others) a better solution to seating in a Seven than the more 'trendy' sports seats. I say this as one who has driven over 100,000 miles in a Seven over the past 1 and ½ decades.
My basic reasoning is that a bench seat can be made to provide the perfect seating arrangement, unlike the 'sports' seat, which in my experience sits the posterior far too high and with little support in the correct places. Obviously this is not true of the full race seats, especially the individually formed ones, but those of you who know me of old will know that I always try to find the cheap alternatives whenever possible.
However, the standard bench seat is far from perfect. It lacks shaped support and still positions the posterior too high in the vehicle. But with a little work it can be made near perfect.
I first performed the following modifications back in 1989 after a tour around Europe, where the original seats had myself and passenger, Steve Porter (how's it going mate?) stuffing sweatshirts in various places to lessen the pain.
A recent rebuild of my car with a different chassis brought with it new bench seats. While these are more shaped then the old they still proved to be next to useless. So, after revisiting my old 'modified' seats once more the new ones were thrown out.
In Cross-section the basic bench seats as something like the following.