You've decided you like the variegated arboricolas. We'll go with an arboricola hedge, but break the monotony with some hibiscus on either corner. We'll plant two red on one side and two yellow on the other. Some cardboard plant and parsoni juniper finish off this simple design.
So you love purple and don't like to work in the garden. Let's go with the versatile silver buttonwood for a hedge and a large shrub. Silver buttonwood is a native plant that needs little care. The Mexican petunias on the far side provide purple flowers all year and are hard to kill. The queen emmas need very little water. Chinese fan palms are slow growing with little pruning requirements.