Saab turbochargers have been succesfully used on 1.6TDs and 1.9 TDs.
For example, one 1.9 TD AAZ makes 220 hp with a Garrett T3 out of a Classic 900.
Like already well described above by conor, they used a couple of different turbos on 900 and 9000 models. The 8 valve and 16 valve 900s also have different trims and wheel sizes in their turbos although they are T3 (except for LPT and Aero which have Mitsubishi Te-05 12b)
The NG900s all have T25s. Meanwhile, the Trionic 7 engine of the upgraded model (OG 9-3) uses a GT17 which is to be avoided as they have poor durability. Aero models, again, have Mitsubishi turbos, this time TD04.
Both the T3 or T25 have been proven usable in VW TDs, while Mitsubishi ones should be even better since they are better on Saab aplications as well.
As for the manifold, on a diesel engine they should last better since EGTs are lower. Someone might argue this is not the case, but if the fuelling is set correctly, a diesel engine will have approximately 2/3 of the equivalent gas engine's max EGT.