About styles from video link.
I found two styles in Henni's Tyros 3 collection, 4-4 Soft Ballad.S795.STY and 8Bt Standard.S589.STY.
I believe that these styles on video are from the same keyboard because I have the disc of another artist and the styles are the same, only using a different chord scale. I'm sure they're before 2000. I think Henni might know where he got two of these styles, and the exact keyboard model. .
About PSR400/500, I think I just get the styles only by recording MIDI and converting to STY with some program like StyleWorks.