Hello everyone. My name is Mark. I am currently in the midst of building my home studio (live and control room) with the help of a local studio engineer, Dan Skye, here in central NJ. The walls are up and the glass thickness has been determined with the help of Rod's book (we both purchased a copy). I am trying to arrange for someone to prep the window opening for the glass installers per Figure 5.3 in Rod's book. By prepping, I mean doing everything short of installing the glass so that the glass company can measure, make, and do the final install of the glass. Does anyone know of a contractor in the central New Jersey area that has experience in prepping the window as Rod provides? Or is there any way to get a more detailed step by step guide to back up Figure 5.3 that I can provide to a contractor? I am trying to save money versus having a window manufactured (Overly or Soundproof windows.com) but may just end up going that route. As a note, the space between my double stud walls is 7 1/8". The reason being that the wall is enclosing support columns. Thanks.