Best 7a sasanqua or japonica for plant architecture?
I have a new circular garden bed that will be incorporated/showcased in a new raised gravel/stone patio area. It's very cloister/shrine-like area, very enclosed and want the tree to be particularly special. We have a lot of old fashioned Asian plants like hydrangea 'Nikko Blue', a big two story weeping cherry which is the crown jewel of our yard, evergreen azaleas, and others. I'm looking at all sorts of options, and am considering a camellia.
I have put in camellia 'Shibori Egao' nearby, where a rhodo used to be, and so far it's been happy.
I'm considering for the circular bed perhaps a second camellia, but I really need the plant form to be worthy of that circle and such prominence, I've noticed a lot of camellia (like the April series which I have elsewhere in the yard) are very informal looking and more shrub-like.
I'm sure good form generally comes with age and pruning, but I was curious if there are others that make a really striking solo specimen.
I was considering perhaps oleifera 'Lu Shan Snow' but are there any others, either early spring japonica or fall bloomers that get into the 8-15 foot range (relatively quickly) that have really attractive architecture? I was envisioning something rather vase shaped and spreading. Any old Japanese cultivars I should look at? Our house is old, I'd love if it was a variety that predated the 1930s.
I'm just looking over my options all over the board, want to pick people's brains.