A very cost effective option for a sub is Furutech's 10 gauge FP-Alpha-3 bulk cable with their FI-11-N1 Connectors. I am using it on my F112 and could hear an improvement over a stock Burmester power cord.
http://www.furutech.com/2013/02/02/1800/
http://www.furutech.com/2013/01/26/973/