I would personally go with the semi dwarf crepe myrtle.
I used to not like crepe myrtles but a resent drought changed my mind.
They got no water and still chugged right along for the duration.
Then I decided that was my kind of tree.
Yes they are done to death here but for a good reason and they bloom all summer long.
And I hate to say it but I have taken a liking to nandinas.
People say they are invasive but I beg to differ.
I have not seen one plant growing where it wasn't planted.
They grow in sun or shade and once established are a cactus of a plant.
When it gets cold enough they turn a beautiful red and have foliage all year long.
And come in all heights for your requirements.
What more could you ask for.
Worth