Um, well, what have you got?

I'm all for buying good pots, but you're going at this in reverse. Pots are frames, basically. You don't buy a frame and ask what painting would work with the frame. You by a painting and look for a frame that complements it.
Release yourself from the thought that this pot must be filled immediately. It doesn't have to be. Put it aside. Enjoy it as the work of art that it is for now. Sara Raynor is a skilled artisan. Her work is definitely art though.
Down the road, you may find you have acquired or made a semicascade or cascade tree that can use it. This could take years.
Over the years, I've purchased a lot of pots without trees in mind. I have a half dozen or so displayed on shelves in my den as simple artwork. Good pots like this one can actually appreciate in value over time, unlike bonsai which tend to depreciate

Also, the pot ain't gonna die on you and you can't make a fatal pruning mistake with it--unless you're a real clutz
