My reference Panna Cotta was from Ristorante Belvedere in La Morra, in 1986 when the place was legendary. Though I have no doubt now that they used gelatin, it appeared at the time to only barely hold its form through technique and good (Chernobyl era) cream. Unadulterated, I still cringe in comparison at flavored Panna Cotta in the US.
In any case, I have impossible standards, and I didn't start out with high hopes for a recipe from Salon, but this works:
It's not the same dessert, but it can be a great dessert in exactly the classic vein.
Skimp on the gelatin, go very easy on the lemon rind (which works with the buttermilk, even though you'd leave it out of the original) and skip the Anisette or Pernod, which is only classy to someone who doesn't know the original. Otherwise, this recipe has great promise. Combine it with what you already know.