Markertek sells Canare GS-6 Premium Guitar Cable which is what some in the know swear by. They have red, yellow, orange, and blue. They even have black.

They also sell Neutrik, Switchcraft, and Canare connectors.
BTW, if you get a wire with a large diameter than the cable will be closer to the shielding (unless you get some really big wire) and have a larger surface area which will likely raise capacitance which is a bad thing. You'll get a lot a high-frequency loss.
Rick