Those are very good points, thanks!what has better seats:
a car that has been to a auto upholster for some custom padding and more material.
legacy / outbacks typically have more material under your but,
but a WRX or STI may have more race style sides but may sit harder under your butt.
re-using maybe problematic, like you may not be able to get seats from a wreck and use them. (no used airbag rules ...varies by state for used stuff).
and such airbags need to be paired to the car. and not many here discuss of swapping seats in such new cars,...so you maybe the first to find out what does not bolt up ...after you bought it.
so adding custom padding to the seat by a upholstery shop maybe best and cheapest.