I recently purchased a Marantz SR6200 which enables me to get the rear center channel. I currently am using Paradigm Atom Bookshelf speakers for the four surrounds, a Paradigm Performance Series center speaker(CC-170), and a Paradigm powered 10" sub. I would like to add the rear center, now my question is do I buy one or two more Atom Bookshelf speaker and add it in the rear center? Or should I buy two dipole speakers and add them as the back left and right, and use one or both of the bookshelf speakers as the rear center? The option I like best is getting two dipole speakers and placing them directly left and right of where I sit, and using the Atom bookshelf speakers as a rear center. Now, if I go that route can I use both Atom Speakers or should I use one? They would both have to be run off the same channel, and if I did use both, how would I wire them? Just stick 2 wires from the same plug on the rear of the reciever? If I go with one more Atom bookshelf speaker I know what to get, but if I go with two of the dipole speakers, which ones should I get to keep the speakers at the same level like they should be? Is the ADP-70 a dipole? That is what I was looking at on there website, it appears to be what I am looking for. The last question would be with the sub. The room is 28' X 20', using 20' X 16' as the living room, so to the right of everything is the extra space. Am I missing something with this sub, should I go bigger. And what would I look for if I do? 12", 14", more power?