I use 18-8 thermostat wire, $85 for 250 feet, you'd need 160 feet. Solid copper, 8x18 insulated wires per "conductor" = 9 gauge, use the whole cable for each terminal. It's easy to strip and terminate if you need to terminate it. If your connections on the speaker and amp can accommodate the size of the twisted together wire so much the better. If you need to terminate you can get gold plated copper spade lugs on eBay pretty cheaply. The cables are a bit unwieldy, but they're tamable. I use 3/8 inch split mesh around the pairs with heat shrink at the ends for a nicer appearance.
I can hear the naysayers already, but if you haven't tried it... Some friends of mine have and have made the switch.
I can hear the naysayers already, but if you haven't tried it... Some friends of mine have and have made the switch.