Alex,
Both the Wersi and Lionstracs Mediastation X-76 do just about everything you described although they both weigh far more than 40 lbs. The Wersi has a fantastic set of built in speakers, the Lionstracs does not have a speaker option. Both can play MP3, MIDI, WAV, Karaoke, Video, and sample files from GIGA and AKAI as well as offer sampling. Each also has 24 BIT DAW style audio recording of 100+ tracks in addition to multitrack sequencing. Both workstations feature extensive editing including BPM and pitch shift in real time and have numerous audio inputs and outputs.
The Wersi is quite expensive but its a great workstation and I feel worth the money. The Lionstracs X-76 keeps getting better every day as Lionstracs is constantly adding new features and updating the software with impressive support like I've never seen from another manufacturer. Lionstracs is working on updates that will allow the user to use streaming samples with the arranger features. Imagine a 1 GB drum kit along with a 4 GB Piano, 2 GB guitar, 2 GB Bass, and 4 GB symphonic strings doing backing tracks for your arranger section. No other arranger or workstation can even touch that!
GIGA files played on the Mediastation sound awesome and being able to store multi GB worth of GIGA sounds on the hard drive is a huge plus. Check out the Mediastation and the Wersi if you have a dealer near you. Both should surprise you as to their capabilities.
[This message has been edited by Ensnareyou (edited 09-17-2005).]