Finding brand new struts would be extremely difficult, just find junkyard assemblies or from a private seller and rebuild them. Bearings/seals/grease/shock inserts.
All very easy things to replace. also you don't need the spring, spring perch, top hats from the 280zx assembly... You replace those with your 610 springs and top hats or go with adjustable coilovers...
You could find "new" brake calipers but most of the time they are cheap china units that don't look or perform as well as oem units