I use the Motu 828x, which is 19"
But there are cheaper options like this: http://www.thomann.de/de/zoom_tac_2.htm (has only audio) or http://www.thomann.de/de/zoom_tac_2r.htm (with midi)

RME does some nice PCI cards: http://www.thomann.de/de/rme_digi_96...p_pcikarte.htm