Disk maintenance apps for Mac OS X

Hi! In the past I've used WIndows 7 for running chkdsk for checking my external XFAT-volume. Do you know a good application for doing the same things on the Mac? Disk utility can not look for bad sectors on the drive, it just checks for filesystem errors. I would love to have an app that could do some more advanced things to the volume. I will be happy to pay for an app that could save me for using this workaround, since I can't use USB 3.0 unless I buy a WIndows 8-dvd, and I wan't do that yet...