chony, for my auto accompaniment (styles) I use LiveSynth Pro (not available anymore), Live - Styler (plays yamaha styles) and sYnerGi GS (modified 128 mb soundfont wavetable). There are other synths that are GM compatible and can load soundfont wavetables. If you want to get up and running quickly I would use sYnerGi GS given that it uses XG compatible drums. Any of the instruments you don't like you can delete and add those you like better.
It is not hard carting around my music PC. My Roland A37 controller keyboard and my PC weighs only little more than an arranger keyboard. Everything is marked and easy to connect. You can, of course, do all this with a laptop today. When I built my music PC a few years ago the laptops were not up to it plus the external soundcards and HDs were also not up to it. If I were to rebuild my system solely for live performances I would like go with the small liquid cooled PCs:
http://sys.us.shuttle.com/ http://www.truespec.com/computersystems/daudio/shuttle/index.shtml My second choice would be a laptop.
[This message has been edited by Frank L. Rosenthal (edited 05-08-2005).]