under $500 used which a/v receiver or processor

in terms of a more detailed and accurate presentation; which brand do you prefer b&k, nad or marantz?

i have a integra 7.1 av receiver. yes it does have a bunch of dsp settings and features i think its pretty decent in sound (not really an expert in terms of high end stuff since i havent heard seperates yet) but the power section is not that hefty i think denons and nads (av receivers) have more in terms of power.thanks for the input though

im looking for a a/v receiver or processor in the used market. not really considering new equipment due to budget constraints. ive seen some b&k, nad, rotel, marantz and integras in this price range which had the original price well over $1000 originally. i have a b&k 2 channel amp 2 psb stratus minis, 2 paradigm atoms, and a hsu vtf 2 sub. looking for a 5.1 receiver or processor that has dolby digital, dts and dolby prologic capabilities. planning to run a 4.1 setup with phantom center. not really thinking about upgrading to 6 or 7 channels in the future; considering the small size of my room. thanks for the input, i also like rotel sound i own a 2 channel integrated that runs my totem mites and they do sound neutral and transparent. i just want to get peoples opinion regarding the best bang for the buck at the used market at this price range.
thank you

any opinions on the marantz sr 4001 in terms of 2 channel music