A little birdie told me that some guy in California who makes some really honkin' big amplifiers with thick aluminum faceplates and massive blue gauges on the front uses these available in terminated form here. SKU you want for 6' XLRs is "GAC-4/1-06NB" (NB = Neutrik gold pin plugs, NS=Neutrik standard, couple bucks cheaper per cable)... you'll need QTY 2 for L/R, total cost will be about US$58 plus shipping...