One other thing to consider with the electrician is that most of the cost is just getting them in the attic or basement to run the line. If you have a little extra money for the romex have them run 2 separate lines with their own grounds to two new outlets. Allows you to later separate amps from frontend or analog from digital. Just make sure that both lines are on the same phase of your panel and that if possible they are on the opposite phase of things with motors / compressors / dimmers.
Dedicated lines really are a big improvement for the money.
Dedicated lines really are a big improvement for the money.