I'd rather see the drivers in B&W shaped pods (to avoid any diffraction). Besides that, I've always thought field-coil is the way to go.
All New Treehaus Audiolab Phantom Of Luxury Open-Baffle FIELD COIL Loudspeakers Review
Many say Field Coil Speakers are the Future of Speakers !
Here’s a review, all speaker drivers have AlNiCo Magnets too !
The link below is not working look here for review