Sorry for bumping...just my two cents in this old thread...
I am using carol power cable ( you know, used for household wiring ) between my amp and sub. i am using a model with 4 wires in it ( two for plus and two for minus ). this way i get star quad configuration, double insulation and a durable flexible cable with heavy gauge that is priced somewhat reasonably. total overkill of course but the benefit is i can step on it and know it will be ok. i have used speakon and i admire how nicely neutrik connectors lock but while it is very solid on the outside internally the connections in it are compromised i would say. since you're not going to move your subs every day i think you will not get much out of the speed with which speakon can be connected and disconnencted. i think you should go for something simpler like banana plugs terminals for wire gauge you can calculate % power loss and percent cost ( cable vs driver ) and adjust until the percent is the same. so for example 2% power loss in a cable that costs 2% of what the driver costs.