A friend of mine runs his 3 stack ( 6 panels) with 6 Quad 2 mono amps these were made for the 57's and i have to say they sound wonderful, deep base fast and articulate and highs mids to die for. i recomend you get another set of 57's and some Quad 2 amps and enjoy. ok maybe extream but the Quad amps are made to run these speakers and do so very well.
When you stack more then one set the base filles out alot and the panels just fill the whole room.