Wanna help with my room?

I am building an addition (1900+sq.ft) to my house and it is going to have a dedicated music listening room, no H/T invloved here. Size of this room isn't that much of a concern and it will have 9' ceilings in it. Do any of you audiophiles have tips you could give me on design ideas. How about demensions? I am up for your suggestions as I trust my fellow audiophiles here at audiogon and their opinions. Is a room totally treated with acoustical dampening a good idea or is that too "dead"? I will have several different pieces of equipment, from planar speakers to tri-odes, going through the room over the years I am sure so I can't give you a 100% positive descriptions of the equipment that will be involved. Looking forward to your help!