RE: "B" speakers. At Gonk's suggestion (see the thread, "One more time: 'B' speaker hookup (long)"), I am using my old 2 channel amp to drive 7 sets of extra speakers. This has worked great. Rather than using the switchbox from Monster (or Russound or Niles), I am using individual controls from Paradigm (which are a copy of the Niles switch) mounted in a single panel in my gear "closet." The individual switches are cheaper than the switchboxes, and the switchboxes are limited to 6 sets of speakers. If you are only using one or two extra sets of speakers, you don't need impedance-matching/protecting controls--wire into the A and B outputs on the extra amp you are using.
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Michael Stano
Outlaw 950
Parasound HCA 1000Ax3
Klipsch KG 3.2s frt & rr
Klipsch KV 3 ctr
Klipsch KV 2 surr ctr
SVS PB2
Sony CDP-CX355 CD
MonsterPower HTS2500MkII
Mitsubishi DD 8020 DVD
Mitsubishi 46" 16:9 TV