First, I'm sorry to be so late getting back to you folks; I didn't realize the questions were on a second set of pages.
I am using a Luxman R-1040 receiver to power all the sets of speakers through an Adcom speaker switcher. The speakers consist of pairs of Velodyne, small Bostons, NHT Ones, Optimus Pro44s and Polk Minis as well as a B&W center channel.