Are you looking for rental apartments in Rio de Janeiro? On this page you have a form you can submit. The flats I have contacts for are located in either Copacabana or Ipanema, they are all well maintained and above average standard. All flats have internet.
Prices start at 160 BRL per night for a studio (a kitchenette) and go up in accordance with standard, location, size, period and length of stay. For holidays, Carnival, New Years and big events prices are significantly higher.
Just submit and I will get back to you shortly.