Looking for a 6" passive soffit mount candidate.

I'm currently looking to remodel my control room, and I want to start with speakers and build from there. It's a terribly small space <700 cubic ft., though it modes out slightly larger due to an open closet at the room's rear and a designed "false/breathable" door in a rear corner open to free air out of the room. I have some sketchups showing a legitimate "near field soffit" possibility. Without dimensions of speaker depth, the current likely mounting will be with the monitors at a 38 degree angle, with roughly 4' 11" between the horns, and a 3' 11" distance to the apex. The 76 degree listening zone will make a narrower sweet spot, so a box with good dispersion is preferred. The first contender in the ring are the Proac Studio 100's, but I'm wondering if anyone has similarly priced options? Particularly with a successful soffit mounting. Also interested in hearing if anyone has mounted the Proacs. Amplifier will likely be a used Bryston 4b, or something similar. I'd like to keep the discussion limited to passive boxes, as it allows a lot fewer cooling headaches. Thanks in advance for any recommendations.