ChristianH wrote:
  - and I assume MIDI interface as well (6 to 8 ports
in+out)
 For Windows I was considering an Emagic AMT8 or Unitor8 interface, 
There is no Linux driver for these.  The snd-usb-audio driver
currently supports multiport USB interfaces from ESI/Edirol/
Roland/M-Audio/Yamaha.
HTH
Clemens