I am renovating my family room. It is open to the kitchen with a cathedral ceiling. The dimensions are 20'x12'x8.5' (lxwxh). The highest point is 9.5'. My couch will be right at the back of the family room. My problem is that only one side of the rear wall exists (about 4' in). Because of the cathedral ceiling there is an upper wall in the shape of a triangle with dimensions 12'x1' (basexheight). I am planning on paradigm studio 20's for the front, cc-570 for the centre and a pw-2100 for the subwoofer. I was planning on using adp-470's for surrounds but my local paradigm dealer said that this would not work since one side of the family room has no rear wall. He told me that I should probably go with in-wall speakers (sa-30). I kind of like this idea since my family room isn't that big. I was wondering if you guys or girls had any advice on how to place the speakers (both rear and surrounds). Is it possible for me to have a 7.1 set-up or should I just stick to a 5.1 set-up? I would post a picture but I have no idea how to. Thanks in advance.