I am not quite following you. How did you change the playlist if the mp3 player if it is 14 feet in the air? Are you synching all this stuff together via bluetooth and your smartphone?o I manually flipped the MP3 player through about 10 or 15 tracks until I finally got it to play "Drei Lilien", the loud German marching song, in hopes of better effect.
Speaking of which, you can probably get some cameras that can communicate via bluetooth and set them to take still photos versus video (which is stored locally on an SD card) and then when you walk past the phone can pull the most recent photos automatically. (Bluetooth is slow but still, better than nothing.)
Most Goodwill stores deal in old electronics. You must be able to find old computer speakers and other equipment for a song at those places.