I'm in Bergamo which is outside of Milan and can't help much with Roma, but I can share some of what I've found so far in Italy.
Biotest nada. I can't find anything Biotest at any of the internet distributors I look at.
It's pretty easy to find dodgy protein powder, BCAA, Creatine, and vitamins. They are sold at just about any Farmacia (Pharmacy), sporting good store, or gym. I buy all of my stuff from an Italian internet distributor (site in English and Italian) and would be happy to give you some info by PM.
How long are you going to be in Rome?