Thanks. I understand the requirements on the receiver side, but I'm just begining to look into the computer side. Some initial searches bring up plenty of information about on-board HDMI on many laptops only supporting two channel LPCM or compressed datastreams (AC3/DTS), however that may be outdated information at this point.
I need to either build a dedicated DAW box (in which case I'll simply install a ATI 4000 or 5000 card as you suggest), or find a laptop that supports HDMI 6 or 8 chan-LPCM. I'd prefer to go the laptop route if possible, both for a portable solution and because I'm space limited. I suppose I should look for one with ATI Mobility 4000 or 5000 series.
The goal is to be able to simply connect the laptop to the receiver with an HDMI cable, and define output channels in the DAW to the HDMI channel standard so the receiver sends them to the correct speakers.