Roland PMA-5 Personal Music Assistant ~$590

$430 at The Great House Of Guitars!

Features: 
 Touch-panel interface offers simple, intuitive and unique operation  
 306 GM/GS instrument sounds
 16 drum sets  
 Eight-track sequencer (Four melody tracks and four backing tracks)
 Roland's intelligent arranger with 100 Music Styles 
 Built-in serial computer port for communication with any computer 
 20 song memory
 store and recall user patterns 
 Headphone jack for private monitoring
 battery or AC operable 
 Import and playback Standard MIDI File (SMF) song data 
     using the optional PC Communication Kit 

Amiga Technologies 'Walker'

 Stackable design (insert whatever modules you want between the base 
    cpu unit and the top drive bays)
 '030/PPC cpu
 Zorro3 & PCI slots