If you want a simple inexpensive amplifier with a remote volume control try this. We use it on our motorcycles and it works great. Amplirider, it can be hooked to 12 volt power and the remote is hard wired but can be lengthened or shortened. Kieth
http://electric-avenues.com/audio/amplirider/
One could then use a simple cord to adapt the inputs to the amp, mount the remote and away you go. good sounds-----volume control and multiple inputs.