OK so I am a little further along with my plans for the 604s. I have talked the project over with a friend who is a accomplished carpenter and cabinet builder. He is recommending 3/4in 12 ply apple or cherry plywood that he can get for about $100.00 a sheet. Due to space constraints in my listening room, I am leaning towards a slightly larger than original (just over 9 cubic feet) Stonehenge III type cabinet. The project will start 2nd week of Sept. I am considering using a power amp in the 80W per channel range. Would like to hear opinions on what would be considered the minimum power required to properly drive these speakers. FWIW my listening space is smallish at one end of the living room, it's about 10 X 12 .