Mixed fountain grasses plus pee gee hydrangea, white echinacea ("White Swan"), plus possibly some oak leaf or Annabelle, plus possibly low white carpet rose. Maybe add Icicle White Veronica or similar. Do Russian sage and grasses near steps.
Kandla Grey Sandstone is a consistently coloured grey sandstone that looks equally good in contemporary and traditional design settings. Here its been laid in a contemporary city garden featuring hardwood seating and rendered planters