Zuki,
Here's some of the info/research I did on the speaker options.
http://www.synthzone.com/ubbs/Forum37/HTML/005980.html As far as styles including from Korg and Ketron boards.... join the psr group for access to hundreds of styles.
http://groups.yahoo.com/group/yamaha-psr-styles/ ------------------
jam on,
Terry
http://imjazzed.homestead.com/Index.html