Tasked with assembling conference room audio/video

Hi, new to the forum and really new to this level of computing/assembling. I've been given the task of figuring out a quality way to set up conference room (two actually) with audio and video equipment. The basis of the install is a media PC with an HDMI output. This will be running a television in one instance and a projector in another.

My problem, beyond being somewhat mentally deficient, is I don't know how to connect the video card completely to the audio video system.

I don't have anything purchased yet but am looking at a Windows 7 setup with an ATI video card with HDMI out. The video/audio will run through the HDMI and this is where I get a little confused; I've been told the audio will be sent to about 8 Bogen Ceiling Mount Speakers (P# HFCS1). And they would like to use a Bogen preamp/amp combo. The Bogens as far as I can tell do not have an HDMI in or out for that matter. My question is how do I get this to work? Do I need to split the audio and video so that the video can go directly to the projector/television and have the audio be sent through a port that the Bogens will accept?

Here is a link to the preamp: http://www.bogen.com/products/pdfs/promatrixpdfs/CAM2m....

and here is a link to the amp: http://www.bogen.com/products/pdfs/mixerampspdfs/GS35s....

It's some kind of 70V speaker system that I don't quite understand. Hopefully this will be similar to a project one of you fine forum members have undertaken.

Sorry for being such a moronical jackass but I've been working on this for most of the day and continue wanting to stick my head in a vice and start drinking.


Best regards and thanks in advance for any help you can provide me.

If I've left out any information just let me know and I'll try to fill in the gaps.