I am hesitant to reply, but I don't think you need MP3ar input as much as you need home automation help. Everything you want to do is readily available through commercial and shareware X-10 home automation hardware and software. Check out the X10.com website. They have a $99 starter kit with hardware and software that you should be able to program for all your needs.
Again, check on some of the home automation forums they can probably direct you to much cheaper alternatives.