Tony, i see that youre a new member, when you have a question dont post it in someone elses thread, do it in your own, each thread is made for an individual and his/her question, it is not a forum for all discussion. Thanks jon.
Yeah, hard to beat. 8 guage would do for a 400 watt Class D, but IMO you're better off getting 4 guage, if you ever upgrade amps, add an amp for components, etc. 4 guage will get you a LOT further than 8 guage will. Plus, $37.50 is just plain out cheap, Walmart prices for stuff that's Monster cable quality. Twister pair RCAs, oxygen free speaker wire, high strand count on all wires including power. 4 guage kit is only 12 bucks more than 8 guage, and gives you flexibility and peace of mind.