Daniel, you do not need to use 12G wire for a total of 80' in length. 16G will run 75' with no resistance added. Use a very good wire either in a 16 or 14 G. I myslef would use Wireworld terra series, very very good wire and is reasonable in price. This stuff outperforms any 12G I have listened to from monster, Liberty, and Ultralink.
Regards,
Glen ___________________ Happiness is living in a padded room with a ball.