If you're looking for seats that are "Europa-like", you might want to check out lotus-supplies.com. They have several seats that look nice. I've seen pictures of some pretty racy seats in a Europa. Since I wasn't interested in them, I didn't pay attention to where they came from. Some of the intatrim seats looked very nice. I think the angle of back might be something to watch if you need leg room. I think I'd want a head rest. I wouldn't want to need one and hit my head on the rear window!
Just a few thoughts...