if you want just mp3s, you could go for one of those little text displays! There's one on the software page of mp3car.com, look at ALCAS.
But if you're like me you wont be able to resist the urge to do other stuff with it. I'd buy a lilliput, unless money is an issue. The problem with the resolution you're suggesting is, you'll have to do a little hacking to get windows to support it. Check with your video card manufacturer too.