Mechanical stuff like engine, transmission, brakes, suspension should not be a big deal since many of the GM cars shared many parts. Its going to be body and interior stuff that is hard to find since that stuff was specific to each model and there is no aftermarket stuff being made for that model. It was similar to a Nova but that vintage also has little or no aftermarket support either. Standard engine was the Buick 231v6. Options included Olds 260v8 and Buick 350v8. Parts for those are not as cheap as say a chevy 350 but they are for sure still out there. Transmission is likely a THM350 with has the best support of any.
Unless the interior and body is totally trashed I would go for it. Its different enough to be cool but not so different that you would be afraid to drive it.
