The new type of 5 Bar K-Jet pump is the Bosch 0 580 254 909 - the old type (Volvo 460821-2 / Bosch 0 580 254 996) is extinct.
As @VolvoHordz said, using the new one as a replacement is straightforward if it's had a previous pump change. If not and the original pump is in there (i.e. the pump with the outlet from the side of the pump body) some mods will be needed to get the new one to fit.