Hi, I am trying to build a project and have little board building exp..What I want is a Sound device walkman,mp3,etc. hooked through a amplifiying device of somekind to a long range speaker,here is the hard part, I want to wire this up using a small 12 volt rechargable battery that I can turn Off and On from up to 150 meters. What I am having trouble with is the amplifier and remote, any suggestions?? I would like to keep cost around 100.00.+ Thanks.