Sounds to me like you want to do some "serious" recording.
Maybe what you need is a "serious" sound card.
Do some research on "professional sound cards." I'm using an M-Audio 2496 card.
ALSA works just fine for my needs. OSS will charge you for a license to get drivers that support professional audio cards.
Make sure you have JACK and its libraries installed. For more info on JACK check htt;://jackit.sourceforge.net. If you purchased your copy of SuSE 10.0, you should already have all the files you need on your installation discs ;-)
You will have to run your recording applications under root privileges. Start JACK first, then start Audacity.
For more info on this check out the following links:
Hope this helps!