Commercial wire for AC dedicated lines

I need some input on which type of wire to use for my 2 dedicated circuits with Wattgate outlets on the end.
I will be using commercial grade AC wire. does that make sense? What can I do for wire? I dont have the no how or anything to twist wires together. I just want to leave my system grounded to the same thing as everything in my house is grounded to and I just want to run wire as-is from my breaker box directly to my Wattgate outlets. What gauge of wire should I use? Should I use solid-core or stranded wire? Should I use copper, silver ect.? What brand and type of wire? My run is going to be about 50 feet. I dont know anything about this stuff and just want it to be easy. I will be doing this soon! So if anyone has any input on this I am wanting to know. I want the type of wire that makes stereo systems sound best.
Thanks!