Look no further then the WireWorld Eclipse,
just look at their patented geometries, all totally isolated conductors of various Diameters, 6-9-s pure Copper ,their dielectric insulation lowest in the industry
and very important connectors ,That are solid Copper, silver . most others especially under $500 use brass, at $450 a true bargain ,I have been using these and their excellent AWG 9 Eclipse Loudspeaker cables , Perrotta consultants give very good deals especially if buying more then one.