At long last I've installed Debian complete with GUI by cheating. I ran Knoppix 3.4 and installed it to the hard drive of my spare machine today. This guide is great for anyone whos in the same position. All the other guides I saw were aimed at Knoppix 3.3 and 3.2, which I could have done but this is nicer. Next step for me will be installing Synergy so I can have one decent mouse and keyboard. Oh and I need to setup user accounts and all that.
Knoppix found almost everything including the firewire, soundblaster and usb's. Dont know if it picked up the multiple video capture cards though.
Ok so after the last few hours messing around the debian box, I'm glad to say I havent broken it yet. I'm learning the pain and joy of apt-get and sudo with the source.list.
I couldnt get the synergy client working at all. some fatal error =
Cserver.cpp.102: unknown screen name 'Knoppix'. Anyway I've moved on to installing mythtv, freevo and VLC.