Your dash panel, carpeting, door pulls and so forth all look black in the photo.
I went to your garage, black wheels look tough looking.
I would go with some light weight aftermarket seats like Recaro Sports if being concourse perfect is not important to you - black of course.
Alternate:
Maybe dye the light parts to match your original gray or cork color?
http://www.diseno-art.com/products/racing_and_sports_seats/recaro_sport_sportline.html
All depends on how original or how boy racer you want to look.