I can't help but recommend Marco Madeira. He is a great guide: knowledgeable, funny and made our visit to Rio de Janeiro a superb experience. A full day in Rio (six to eight hours) costs $270 and includes Sugarloaf Mountain, the statue of Christ the Redeemer and the old part of the city. Price includes car and tour guide but not admission tickets.
Marco Madeira, firstname.lastname@example.org