I'm with the other guys, I'm a fan of rebuilding and reusing originals. I've replaced a lot of springs in different types of cars and used a few different suppliers, I've never been completely satisfied with ride height when done, even after letting them settle a while, so I generally end up going back to the original springs. Sometimes new springs hit it right on the money but 80% of the time I haven't been that lucky.
If you go the new route, I'd research here what others have used to obtain a correct stock ride height, if that is in fact what you're after. It's a pain to go back and do it over again.