I would recommend you get a receiver with auto parametric room correction (i.e. YAPO, etc) and about 100 Watts per Channel over 7 channels with low distortion (i.e. like 0.07% or lower.). You probably want at least 2 HDMI inputs if not more. You should get the latest audio/video capabilities such as deep color, HDMI 1.3 etc. I would look at the top of the line receivers in the big box stores, but then order it over the internet and save a couple of hundred dollars. Some of the higher end receivers are only available at specialized retailers or at retail price over the internet. If an item is in a big box store, then it is probably available at a big discount over the internet.
Many seem to favor an Onkyo unit which delivers a lot for the money. I personally favor Yamaha and Denon as they make top-of-the-line receivers and a lot of the technology trickles down to lower price units after a couple of years. My Yamaha receiver is a couple of years old, but it met all these requirements (except newer A/V capabilities) and it has a little more amplifier power. It was $550 over the internet. I have never had the problems of distortion or auto shutoff with 120W/Ch amplifier power. You can always turn the volume down rather than buy too inexpensive of a receiver.
I don’t know why you would not keep your speakers as opposed to trying to find something at a lower price. Probably the best speaker/subwoofer set for the buck that has good low extension bass is the lower priced SVS package for about $1000 (5.1). HSU and AV123 also have good speakers in roughly the same price range.
