Most “disappeared” speakers.

From all the speakers that I have heard it is usually the monitor speakers that do the disappearing act best. The less MDF to rattle around the less the speakers reveal themselves. I like the Chapman speakers sound good, they are transmission line speakers and the usually cabinet rattling bass rear waves have an escape route that seem less obvious then sealed or ported. 

My most wide soundstage speakers were the old Bose 901s. Distance from wall and more importantly wall material are critical however. I had an apartment with brick wall (3 deep) separation and the sound was magnificent. Moved to a house with drywall and I couldn't sell them fast enough. My message: Room is everything. Good luck!

Ohm 5000; lots of power behind them; don’t be afraid of adding a sub.

Oh and Andy is right....on both counts.  The room is everything.

When you get a chance try this. Blind fold yourself and have someone guide you towards a dynamic speaker. You will know right away when you are right on top of it. Do the same for any full range ESL and you will walk right into the speaker.