We will be traveling to Paris in late October... one couple in their 70's and one younger family of four. Ideally, we would like to find two places in the same building... one larger and one a studio... or a 3 bedroom 2 bath apartment. We'd prefer the 11th or 12th arr. Is there an agency that provides this service? When I look online at the two rental option, I can't tell how close they are to each other. Any advice would be appreciated.