In my experience, many if not all of OEM SAAB 900 Classic fuel pumps from 16V ‘90+ turbos had a Bosch pump cartridge, like this:
The Bosch number is: 0 580 453 945 (0580453945).
It is possible to retrofit a Walbro fuel pump cartridge with minor adaptions, but I found a lot of confusing information on the required inlet/outlet diameters and the fuel flow.
After helplessly searching for the correct fit I found that the “BOSCH ELECTRIC FUEL PUMP 69576” item offered by a few sellers on ebay at $40-45 is the exact same Bosch cartridge with the correct Bosch number. The 69576 PN seems to be some quirky US catalogue number.
The pump safely arrived in Europe, the total cost was much lower than whatever is offered here, and it’s an original Bosch pump good for another 20 years!