I would replace the shocks. I like Bilsteins. If you use Koni, put the spring perch on the upper setting.Any suggestions on spare parts to buy before taking apart the rear shocks? Should I replace the shocks while I'm in there, and any other parts that are probably all rusted and worn out?
Spring spacers are the only way to get ride height in spec. It is not a cheap replacement, just and adjustment to ride height. As noted Saab springs tend to sag, even new ones.