i'm in the same boat as you, keep the originals or go with something else, seat swapping would be down to finding something you like i guess and seeing if it would fit, in theory any seat should be able to be made to fit its just what it looks like in the car, i may redo my originals, have also thought of mx5 seats, my son has one and i find them comfortable, with the addition the speakers are built into the headrests so with these fitted the possibility of moving the speakers from the doors is open to you, and i used to own a ford probe and found them to have some of the most comfy seats i have sat in so would love to see how they look too, so really the answer to your question is pure personal choice, and if the car has any sort of historical significance then original would really need to be adhered to....[8D]
there thats probably totally confused you now hasn't it.... [;)]
the project at birth, watch it evolve...I hope...