My house is an old plank board nightmare. Currently remodeling two rooms upstairs. I want to add three outlets and ceiling light to each room. I do not dare to add to existing outlets. Was thinking of running one line up to the attic and adding a subpanel. If I go this route, any ideas on gauge of wire from main to sub? Was planning on 12/2 for outlets and light. Biggest thing that might get run is a window unit AC.