I posed a similar question a few days ago and, following suggestions from members, two of my choices are going to be Brunnera Jack Frost and Pulmonaria Blue Ensign. There is a supplier of both through this site. I love to know what you buy and see some more photos.

Perennials - hosta, epimedium, heuchera, campanula portenschlagiana (front edge), hellebore, gillenia.
Shrubs - sarcococca, skimmia.

Would also suggest dwarf bamboo, carex and festucas especially along the front there.....would also tie in with the Asian bust.

For a cascading habit at the front, how about Opiophogon (small black grass) or Hakenochloa macra (lovely green). Glad to see you already have Nandina!

I would also tuck some cyclamen in there - they enjoy dry shade

A fern would make a nice contrast too, and euonymus fortunii is a cheerful evergreen variegated shrub easily clippable to the size you need. This is a good time of year to buy a hellebore as in a week of two the ones in the nurseries will be in flower and you can choose one you like.

Thanks to all for your advice, will get some of the plants
mentioned, I did have Bamboo but it took over had to get it dug out, have kept some in large pots. looking forward to seeing what it will look like later in year.