If not the H&K SP89, maybe you are thinking of the civilian version of the H&K UMP or could consider one.
There are three versions of the UMP: the UMP45, firing a .45 ACP cartridge; the UMP40, firing a .40 S&W cartridge; and the UMP9, firing a 9X19mm Parabellum cartridge. Apart from the different chambering, all versions feature the same basic design, the most noticeable difference being the curved magazine used on the UMP9 (whereas the UMP40 and UMP45 use a straight magazine). All three versions of the weapon can be converted to any of the available chamberings via replacement of the bolt barrel, and magazine.
The USC or Universal Self loading Carbine is a semi-automatic version of the UMP that could be owned by private citizens for sporting purposes. It was designed following the AWB of 1994 in the United States and conforms to those standards. Changes from the original UMP include a "thumbhole" type stock and grip (versus the pistol grip of the UMP), longer barrel, limited 10-round magazine, and semi-automatic only trigger group and action.
Jack