the nissan parts shops like muneer etc. have them or go to AH Sons near plaza - if your units are trash they will advise to install new, if they are rebuildable - they can rebuild them.
Make sure all rear bushings are good and intact, It has a lot of them, They used to be and still are quite expensive to repair correctly. Bad bushings cause rough ride too which make the rear struts seem bad while they are not. (same case why aligning the B12, B13 sunny was expensive compared to other cars)