We stayed 4 nights at Adriana's apartment, which is perfect for 2 persons. You are in a very sweet and calm area of Roma but incredibly close to all the monuments and sites you want to visit! It's also easy to walk to Trastevere or Foro for a drink and restaurant and for the rest you can take the bus and the metro close by.
Plus Adriana has made it the easiest for your journey planning with a book full of advices on restaurants and itineraries. A superb stay in Roma !