A Yamaha RX-V657 is probably one of the better ~$400 recievers out there. I have the RX-V557 and it fits the bill just great. Sounds awesome. Yamaha's crisp and neutral sound fits very well with the axioms. HK's are a bit more warm I have heard.
I don't use any video with the computer because I'm at a computer. If your TV upconverts the signals well anyways, I don't see a point in getting a receiver that does the exact same thing. I know some receivers have some pretty complex video processing, but prepared to lay down a chunk of change for one of those. Also, some people find it frustrating and confusing to someting as simple as turn on a TV and get the audio working if it goes all through the receiver. If your kids like turning on the TV, that might be an issue.
For me audio quality far surpasses video quality in terms of priorities go, so I may be a little biased.
