With that budget, holy hell...
With that kind of money, I would get in touch with Danny Richie from GR Research, Paul and Dennis from Philharmonic, etc and just see what kind of custom magic they could work up for you.
Personally, with my extremely modest budget, I am keen to try out this:
Super-V
Get some really nice, USA built cabinets from any number of custom cabinet makers, maybe Salk, etc.
These would also satify your idea of changing things up a bit due to it being an open baffle design, using a pro audio driver, and having four built-in open baffle, servo subwoofers.
You could probably have them auditioned in your house for shipping costs if you asked Danny...