I made my own years ago with the help of this MP3 Module
- before the days when every dog and his owner had an iPud and/or flash drive sized players.
Portable - Yep, AFAIAC since it's used for camping, LAN parties, whatever.
Battery Life - Haven't flattened the car battery or the mains yet.
Song Capacity - Heaps or just choose another drive/disc.
Output - As powerful as whatever amp you plug it into.
Remote Control - You betcha, can program it to accept almost anything.
Currently equipped with a 80GB 3.5" HDD with >9900 MP3s but I'm looking to downsize to a 40GB 2.5" HDD since I'm only using about 50% of the 80GB.
Otherwise, have a browse through ChinaVision
's selection of HDD enclosures - most play media files.