as I've seen this kind of enquiry to pop up every once in a while: for those of you who need an English speaking accountant / tax adviser (regardless of whether you are a sole trader or have a company) in Milan, feel free to contact the following firm – ask for Davide (Suriano):
STUDIO SURIANO Viale Stefini Protected content metro station MM3 Sondrio) Protected content Protected content
They already have foreign companies as their clients (I of course wouldn't know which companies!), so they're familiar with international fiscal aspects too.
I wouldn't be able to say anything about their fees as they depend on what services you will need – book an appointment and see what they can offer and whether they suit your needs.
(PS. Yes, I'm their client, I've been that for some years now, but I've always taken care of everything in Italian since I've been living in Italy for several years!)