Buy the Nimbus (or something in that general price) now and get off the upgrade train, if not permanently, for at least a longer period of time. The Stiff Breeze is another $2,500 speaker, and while it may be a great $2,500 speaker (I have not heard it), it is not the answer to "What speaker for $10k?"
If you want to make a significant leap forward in the quality of your sound reproduction you can't make it taking small steps. Just my experience, FWIW.
Best of luck in your search.
Jim Perry