The Fujitsu drive that you listed is a SATA (serial ATA) drive; I don't think the iBook takes SATA drives. All are 5400, which I would recommend for a speed increase over the 4200 drives Apple typically uses in iBooks (and did use in PowerBooks). I bought a Samsung for my Cube awhile back because of its low noise and power consumption and am very happy with it. If these are issues for you, you might want to check the reviews for noise and power. According to a review of 5400 rpm notebook drives by SilentPC http://www.silentpcreview.com/article207-page1.html
, the Samsung is the quietest of the drives, but not the fastest.