One bass player who has a style that reminds me of Taiji is Markus Grosskopf, from Helloween...
Another one is Billy Sheehan, from Steve Vai's band, Mr. Big, Talas, Niacin, David Lee Roth's band, etc, etc...
But I really can't remember other bass players that manage to use slap in Metal songs the way Taiji does... I love his slaps in songs like "Xclamation" and "Give Me The Pelasure", and "Twisted" or "Everyone Lies" from Loudness...