Hello I own a 27" Imac (Intel Base) Lion operating system and I also have a Frisby FS-5015a 5.1 surround sound system that I want to connect to my Imac. Could you please tell me which external sound card I can purchase so that I can watch my dvd's on my Imac or what I need to do to make things work properly. I am a newbie to this so I really appreciate your time and patients with me.

Thank You Very Much