Custom Thin Touchscreen MP3 Players

I need guidance and hands-on help to create two bespoke touchscreen MP3 players that are slightly smaller than an iPhone, noticeably thin, lightweight and visually striking. My goal is to tailor both the hardware and the software, not just re-skin an off-the-shelf model... (Budget: $10 - $30 USD, Jobs: 3D Modelling, Arduino, Embedded Systems, iPhone, Mobile App Development, PHP, Prototyping, Software Development)