Here’s another source for rotors, including cross-drilled fronts, if you want to spend a little more:
http://catalog.worldpac.com/mercedesshop/sophio/wizard.jsp?partner=mercedesshop&clientid=catalog.mercedesshop&baseurl=http://catalog.mercedesshop.com/&cookieid=1CQ0J3JZ426M1D2KJ2&year=2001&make=MB&model=ML-320-001&category=N&part=Brake+Disc