8 track audio interface

I am working with Audacity 1.3.5.c on Mac OS X 10.5.8 (Macbook), looking for an 8 Track Audio Interface with minimum 8 Outputs and 8 Inputs. It should work on USB 2.0, or better, on firewire. The interface shall be used for artistic sound installations. I have read a lot about compatibility problems in various forums. Does anybody have an advice which hardware is the best choice? And maybe there is something for sale?

You shouldn’t multiple post. I’ve locked this topic.