These are available on this site.
If you look under the Home Page Welcome box you'll see a tab for the PSR-SX900.
Click on that, and scroll to the lower half of the page, where you'll find all the styles included as standard with both the SX900 and the SX700.
By clicking on each of the headings BALLROOM for example, you can download a ZIP file of the styles within that (and every other) heading. Click actually on the word, not on the surrounding area.
There's also downloads of original styles for pretty well all more modern Yamaha arranger keyboards on the same page.
Hope that helps.
