Open Source and Free Software

[div class="excerpt" style="margin-left:1em; border:1px solid #bfbfbf; border-radius:0.4615em; box-shadow:-1px -1px 3px #bfbfbf inset;"]About Audacity

Audacity is a free, easy-to-use, multi-track audio editor and recorder for Windows, Mac OS X, GNU/Linux and other operating systems.

http://www.audacityteam.org/about/
http://www.audacityteam.org/download/linux/

It can do 24/192, but you'll almost certainly need some ADC hardware interface to get audio at that sample rate into your computer. Before buying any hardware, you could try out Audacity with your built-in soundcard to see if you like it (and hopefully also determine if it will do what you need).

I'm not sure if it can do surround sound though - I believe it can export multi-channel audio files (probably requires a plug-in), but don't recall a way to monitor them in real time.

I don't know of any quality free open source video editors, but I'm not a video guy so I wouldn't really know.