I am thinking about adding 1 or 2 surround back channels to my HT setup to take advantage of DD-EX and DTS-ES, and was wondering what most of you use. My HT room is 26 feet long, 11 feet wide, and the wall behind my seated listening position is 6 feet behind me. Do you recommend 1 or 2 speakers for rear effects? How are the 7 channel modes on the DA4ES processor? I think I'd like two channels, but will definately go w/ only one channel if that is all that is necessary. Also, will a satellite speaker(s) do, or do I need bookshelf speakers? After all, they're only for effects, right?