Agree with ncx's expert suggestions. I may be doing the tech refresh of my HT soon.
AV Receiver is the heart of home theater, so get a good one. I am waiting for the Yamaha RX-V2800 /RX-V3800 which will have HDMI 1.3a. Denon and Onkyo are also good. Should go at least 7.1 to be tech up-to-date. I have heard on AVS forum that Velodyne speakers are also good for the money.