Inside Out Wall and Ceiling Alternative

I have posted a couple of times looking ror suggestions, and have decided to take the plunge and start construction during my Winter Holiday. I am going to do the build a single room at a time, starting with a drum room. The room is very small, 340cm x 340cm with a 250cm ceiling height. There is a window on the north wall and a doorway on the southwall that will lead into the main CR. You can see the layout and pictures at http://www.two-eight.com/studio The sudio is being built on the first floor of our newly purchased (used) house. The building is wooden, with the current walls being wood with a thin application of Stucco or similar on the outside. Because of the small size of this room I have decided to use the Inside Out design that John described over in the SAE material, and that was used by JohnGardner in his build. I will have a number of questions, but the main ones for now are... 1. Like the build mentiond above, I don't feel that the outside wall is airtight enough to act as a leaf. I will probably add a layer of drywall to it to beef it up. Is this assumption safe? 2. The window in the north wall. I would like to keep it, as it acts as a natural light source. If I keep this window but replace the glass with something thicker, and then have another window in the new wall (of the inside out section) would this give me a serious weak spot? 3. I will use a standard Japanese Airconditioner unit. These mount to the wall and have pipes that run to the fan unit on the outside of the building (sorry, I left Ron's book at the office and can't remember what this system was called). As long as I caulk this, can I assume it won't create to bad a sound proofing failure. 4. Finally, I am having a horrible time finding Resilient Channel in Japan. I have someone who is willing to import it for me from the states, but it will be very expensive and won't get here until after my holiday time is finished. I have investigated, and the Japanese seem to use a bolt system for their ceiling sound proofing. The bolt attaches to your ceiling josts, and drops down to a second head that connects to another frame. There is a rubber polymer that acts to cut down on transmission. The two ends can be adjusted to highten or lower the ceiling. I am not completely sure if this would be a suitable replacement or not, but it might be the best I can do... Does the picture attached look like this system would work? I plan on using the room to record rock drums, and need to isolate the drums away from the neighbours (house about 5 meters away) and the family upstairs. The combination of music projects (loud), limitted space, expensive costs, etc, really make me feel like this is almost undoable, but I really want to give it a go. Any suggestions or tips would be greatly appreciated. I will post more as the project gets further along.