Colin, as far as I know, true casu marzu is prohibited by law these days. You will have to find some cheese speakeasy in Sardinia. I guess Mirko Siddi would be more qualified to point you in the right direction.
Oh, and Petals - from what I read, the live maggots can cause problems, too. Like burrowing into the intestinal walls. Hrm....
As for myself... I am pretty adventurous, but insects and maggots in particular are a problem. One that I may tackle one of these days. Or not....