I don't have time to read the whole thread, so I'll TMN myself in advance.
However:
OH bought a GM Saab 900 (the first GM one) when she needed a cheap car quickly - she gave £500 for it I think. It was the 2 litre non-turbo petrol. It had about 150k miles on, I think. It had a patchy service history and we had it two years and it never missed a beat: it started when you needed it to start and stopped when you wanted it to stop. It took a fridge freezer whole, and also shifted more stock than I care to calculate. I had a much newer car at the time, but that let us down a few times (same fault incorrectly diagnosed to be fair to that car) but we always knew the Saab would go.
And, on top of that, because she only paid £500 for it, and in the end we didn't use it much we never serviced it either - not so much as an oil change. And it still soldiered on. No rattles, no squeaks, no rough running. It just worked.
The 1.9 diesels are the same engine (more or less) as in any other 1.9 diesel, and it's ultimately a Fiat design. These have their faults like all modern diesels; it's essential to change the timing belt and water pump at the correct intervals, and if you run them around town you will probably get a blocked EGR valve. A good old 'Italian Tune Up' keeps them sweet: I had the 2.4 version of the engine (the same thing but with 5 cylinders instead of 4) and as I was much younger then I drove it in a more 'spirited' way and never had a problem. You will read horror stories about the 1.9 diesel, but remember that it's fitted to a heck of a lot of cars and vans - every 1.9 diesel Vauxhall, Fiat, Alfa and Saab have basically the same engine, albeit with different 'extras' (turbos and intercoolers of varying sizes and different software).
The idea that Saab's are basically Vauxhalls is slightly unfair. Saab were supposed to build cars based on the same sized Vauxhall, but they weren't very good at following instructions and changed so much that there are surprisingly few similarities. For example, Saab decided they didn't like the Sat Nav General Motors provided them, so rather than do as GM told them, or even write a new front-end for the same basic program, they wrote their own Sat Nav code from scratch.
The 9-2 sold well here, so parts won't be a problem. Mechanically there are a lot of Vauxhall parts, and although the panels and all sorts are different, there are plenty of scrapped ones about to keep you going for years.
