Chuck, sounds like a fun project! I would love to see a bird bath in the center, or a dwarf Japanese maple..... since iris is my favorite flower, I would have clumps of Siberian and tall bearded near the center...... Asiatic lilies, & daylilies, Cone flowers next, along with Shasta daisies....short summer phlox, like Red Riding Hood....perennial geraniums......some annuals for the outside edging......All those plants are hardy in your area, & will give you color all growing season....My gardens are all raised beds surrounded by stone walls...the front ones are backed by a white board fence......