This generation of 900 does suffer from body roll. Check for signs of cracked springs and leaking shock absorbers, you could also try bouncing the car at each corner to check the return rate. If you do decide to refresh the suspension, then it will be worth doing the bushes as a 'while you're there' job. If you decide not to replace them with stock items, make sure you drive as many modified or 'uprated' examples as you can because if you decide your new ride is too firm it's not an easy process to reverse. It's also likely to be an expensive one. Few suspension jobs go smoothly so if you're doing it yourself make sure you've got heat handy as you'll probably need to warm up siezed bolts and burn out stubborn bushes. You'll probably also need a decent press to get the new items home. Likewise, if you go for a garage, it could take a bit longer (and make the bill a bit higher) than originally expected. Which leaves you having to answer an important question: how much is the car worth to you? It would be quite easy to refresh the suspension and end up spending close to the purchase cost of the car on that one job. How deep are your pockets? Are there any more urgent or pressing jobs that would require funds first? Good luck with whatever you decide to do.