McMaster-Carr has many metric screws. You didn't say the type head you need. Here is the metric screw page:
http://www.mcmaster.com/param/asp/SelectFamily2.asp?reqTyp=parametric&act=SlctFmly&fam=cap,drywall,acmerodgen,machine,acmeprelead,selfdrilling,set,sheetmetal,shoulder,scs,bolts,threadcutform,threadrod,thumb,weldscrews,woodscrews&val=,,,,,,,,,,,,,,,,&desc=Metric+Screws&sesnextrep=602128688187958&ScreenWidth=1024&McMMainWidth=804.
http://www.mcmaster.com/param/asp/SelectFamily2.asp?reqTyp=parametric&act=SlctFmly&fam=cap,drywall,acmerodgen,machine,acmeprelead,selfdrilling,set,sheetmetal,shoulder,scs,bolts,threadcutform,threadrod,thumb,weldscrews,woodscrews&val=,,,,,,,,,,,,,,,,&desc=Metric+Screws&sesnextrep=602128688187958&ScreenWidth=1024&McMMainWidth=804.