Details on wiring my house for sound

Thanks for the responses to my previous thread. More questions, however. I have a Square D fuse box with six sockets. Some are fitted with the Fusestat devices. I presume these are NOT best, as they involve another layer of contacts. Anyone with experience with these. Also, the box says to use only copper wire, but the contacts in the sockets look to be aluminum and are raised. Should I look at other boxes? I know Sq D is high quality and the box is quite heavy. Thanks for any thoughts.