Please someone make an mp3 player that has precise progress bar, ideally controlled by a physical slider or potentiometer. Also please add an option to slow do

Please someone make an mp3 player that has precise progress bar, ideally controlled by a physical slider or potentiometer. Also please add an option to slow down or speed up the material with reasonable anti-aliasing and an option to retain pitch. Please make it so that you can scroll through thousands of mp3s and preview without interruptions. Let me store cue points recallable by dedicated physical buttons. At this point you may see that I am actually describing professional DJ player, but these things are mad expensive and bulky.