Wayne, for surround speakers, what do you think of using a waveguide paired with 2 - 4 6.5" high sensitivity drivers. Have you seen the center channel, dubbed "Malcom" (for Malcom in the middle) http://www.diysoundgroup.com/forum/index.php?topic=11.0 It looks like a derivative of this would make great surrounds when the drivers and waveguide is flipped upside down and mounted high up in wall to ceiling corners and angled down.