If you plan on buying and modding an NG900/OG9-3 1999 was the best year as it has all the updated parts that switched from the NG900 to the OG9-3 but still retains Trionic 5 engine management as opposed to the newer Trionic 7. T5 is much easier to tune and also allows for a cheap MBC where as with T7 you will have a much harder time tuning if doing it yourself or end up spending big bucks on a mailbox tune also an MBC only wont work with T7.
If you end up getting the saab make sure you check out
www.saabcentral.com and
www.saablink.net