I use a Behringer A500 2 channel amp for Zone 2 and think is does a great job. It is relatively inexpensive (less than $200) and think it would work fine for the rears.
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Outlaw 990/7700
SVS 20-39 PC +
SVS MTS-01 towers, MCS-01 center, MBS-01 surrounds
Behringer A500
Samsung PN58A650, DirecTV HR-20 700
Sony CDP-545, Phillips CDR 765
Oppo BDP-93, Panasonic DMR E515
Technics SL-DL5
Squeezebox 3
Remote Harmony One