Unless you have access to exotic conductors, the 'amount of metal' (i.e. gauge) of the cable/wire is the best measure. That having been said, if decent gauge lamp cord isn't good enough for you, paralleling 2 or 3 strands ought to do the trick. Thank you Dr. Ohm. If you are concerned with increasing capacitance(?), a cable containing the same amount of metal as the 3 lamp cords would have the same capacitance issue. Electric current is remarkably disinterested in other details except for loops in the wiring and oxidized connectors.
Do speaker cables really make a difference ?
Thinking about buying a different speaker cable. Do speaker cables really make a difference?