Gardenias would be lovely there, and they are evergreen plus stay about the size you want. A little slow-growing though.
There are now some varieties available that re-bloom so you wouldn't have one flush of bloom in the spring, and then nothing. 'August Beauty' is one that re-blooms and there are others.
The other one I'd consider is Sambucus 'Black Lace'
Elderberry (Sambucus nigra Black Laceโข) although it is deciduous. The foliage is just lovely, plus they are hardy and grow fairly quickly but take very well to pruning to keep them at a size you will like. It only blooms in the spring, though, but then has berries through the summer and fall for interest, and they attract birds. The foliage varies from dark green to burgundy, and turns a lovely red in the fall.