Building your own AC cords is a good option as long as you use cable that is meant to be used in this application! Just be ultra careful when doing the wiring of the plugs that no stray strands of wire can potentially touch each other. I don't think the use of shielded AC wire would make much difference - the shielding is more useful for the receiving end, i.e. low level interconnects. However if you can get a bunch of shielded AC wire of high quality for not much money, I guess there's no hurt in using it. Just please be careful - 120VAC can be "uncomfortable".

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The Soundhound Theater