@Ghostrider
Power rating at 1Khz is a useless number. No source is a single frequency, except for a test tone.
Look for 20Hz - 20Khz number. This is the full audio range.
Unfortunately, most modern AVR manufacturers always specify 2CH driven, when you have 5/7 channels on the AVR.
As far as power is concerned, there is a direct relationship between speaker sensitivity and dB level.
PSBs are pretty efficient speakers
T5/C5 - 88/90 dB (anechoic chamber/listening room)
B4 - 85/87 dB
Assume you will settle on listening level of 96-99 dB (loud enough not to give you a headache).
T5/C5 need 8-16W of power
B4 need 16-32W of power
Pretty low, isn't it. A power output with 50W is sufficient headroom even with transients.
You also have a sub to take over LFE duty.
Denon and Marantz are very capable AVRs with a wide range of products.
SR5010 is 100Wpc (20-20K range)
X2200 is 95Wpc (20-20K range)
If your listening area is small/medium (less than 200 sft), also consider Marantz NR1605/1606.
Similar features to SR5010, but 50Wpc, smaller profile and definitely cheaper.
With the savings on AVR cost, you can probably buy/upgrade other components; BDP for video or DAC for digital audio.
I have a NR1605 and am very satisfied with its performance.
The one crib I have against Denon and Marantz: their user interface is very slow.
Cheers,
Raghu