For video, try videogon.com
The Cambridge Audio 640R does all you want, including 3 hdmi inputs and full 7.1 preamp outs. It's about $900 new. I've got the 540R and like it quite a bit. This is the second CA amp I've used and I think they have great sound. The 540R has preamp outs (6.1) and 2 HDMI inputs, as does the 340R. If you can live with either two inputs or use an hdmi switch box, you can get the 340R for $600 new.
Also, I don't use one and don't know about the quality, but you can get remote controlled HDMI switch boxes (3 or 4 inputs) for $30-$80. Getting a cheaper AV receiver that just has one hdmi input and coupling it with a switch box might bring down your costs quite a bit.