Lots of the Saab dealers stayed open to service cars.
Neo brothers sell most parts online.
If you join UKSaabs website you can get all the advice you need plus lots of members around the country have Tech2 diagnostic machines that they’ll happily run on your car for a cuppa and a biscuit.
The last 9-3 was a “£35k car being sold for £25k” so they were pretty decent.
THe 1.9 TiD needed a cambelt at 72k/8yrs up to ’07 or 90k/5yrs onwards. The water pump MUST be changed at the same time (or sooner) as they fail prematurely.
No personal experience of the 1.9 TiD. It’s a Fiat derived unit IIRC – which isn’t necessarily a bad thing.