That's an interesting point about the lamp cord versus speaker wire. And yes, I think the existing old wires are 20 gauge, very light-weight. And probably not in the best shape. My plan for now is to run new wire to the "big" good speakers (megabucks when Dad originally bought them ages ago) and test out locations for a couple of other speakers by reusing the old wire, and then see how much of the new roll is left to wire those if I need to. I also have a sound system in my office but the old wires there are shorter. In the living room they're probably 20' away from the receiver.

Meanwhile, I'll make a list of the various electrical ratings of the equipment to see how they line up (after reading JiK's instructions it sounds like they can mix and match at this level without too much trouble).