Hi Stella,
We used HouseAroundItaly but our situation was slightly different. We had found the property we wanted and we just used HAI to do the purchasing. The ladies at HAI were all very nice although there offices (at Pescara airport and in an apartment building a couple of blocks away) seemed to be overcrowded and in some confusion. The purchasing went along very slowly but they seemed able to overcome the problems. We became very upset with them after however. The sale was completed in December 2006 and we went to our house in May 2007. We said we would pick up all the paperwork then. When we arrived they hadn't got all the papers and told us to come back a week later. This went on for the 4 weeks we stayed and finally 2 days before we left we literally had to threaten them to get the documents.
I would say the people are pleasant and seem to know there way around but I wouldn't trust them to handle the legal work. ie hire your own notary and geometre if required.