Cliff notes: use 10-gauge romex and attach both lines to the same leg of your panel. Use 20-amp breakers and get at some form of decent outlets like the PorterPorts offered by a member here.
Time for dedicated outlets!
I would like some advice on what exactly to tell my electrician to be sure I get what I need. Is just saying that I want two separate dedicated lines to the listening room sufficient or are there other key fraises that should be included in my description of the work I would like done?