Behringer A500 amp
Chako,
Here is a link for the Behringer for a good price:
http://www.bhphotovideo.com/bnh/controller/home?O=productlist&A=details&Q=&sku=373631&is=REG&addedTroughType=search
This is an (outboard) amplifier. It has a single set of analog line level inputs (RCA or XLR connections) and stereo speaker level outputs. It is stable in to 4 ohm loads and can deliver over 200 Watts per channel. This model also happens to have a volume/gain adjustment to allow you to set the max power/volume and can be bridged to make a 500 Watt mono amp.
In contrast, a $200 stereo receiver will include an am/fm tuner, multiple analog and digital audio inputs, and probably some video switching. Most in this price range will have an amp with 50-80 Watts per channel and are only suitable for 8 ohm loads. When you start dividing 50 watts by 6 or 7, you have less than 10 Watts per channel which wont be too loud depending on the speakers and room size.
Also, the digital output is just a passthrough of 1 or more of the digital inputs. An amp like the Behringer A500 does not have any digital inputs. Another connection idea: Connect the amp to the main pre-outs on your pioneer. This would work for any analog or digital source, however, the amp would always have the same source as the main HT.