I am going to Paris on my honeymoon and have booked The Madison which seems to fit some of your requirements. It is in the 6th on the Blvd. St. Germaine. I am not sure if the rooms have balconies but I have read (I can't remember where) that some of the rooms have views of the Eiffel Tower. Also, I believe it is directly across from a Metro and famous Parisian cafes (Les Deux Magots)as well as walking distance to many of the major sights. Another advantage of this hotel is that it includes breakfast, which I have found not to be the case with others. You can look at reviews of this hotel and others and make reservations at: http://digital.france.com/hotels/

The hotel's website is: http://www.hotel-madison.com/room.html

Good Luck,

Angela