If you want to grab some Rancilio branded cups, you should probably contact your local Mocopan roastery. From memory, Grinders also use Rancilio, so you could try contacting them.
Many branded cups tend to be relatively cheap, seeing as they are thrown in as freebies. In that sense, its quite remarkable that La Marzocco brands ACF ... although perhaps not surprising, given the $$$ that you pay for a LM. I remember thinking that the Rancilio cups werent that nice last time I saw them, but, as with most cups, Im sure that theyll do the job.
I made a point of keeping quiet about the ACF cups whilst everyone was going for the Nuova Points, but we certainly have them in stock: http://www.venezianocoffee.com.au/equipment/first-pour/product71?pageNum=4maybe Epic Espresso in Perth still has some ACF cups left... undecided
As far as I know, we have only had one cup breakage in shipping ACFs to people and we have changed our packaging as a result.