Nowhere in Brazil is like Ibiza, I can tell you that. Ibiza is unique, which doesn't mean you won't have A LOT OF FUN here. It depends on what your expectations are. For electronic music you should definetily go to Ibiza. For any kind of fun and for beaches, Brazil is a better option.
Remind to come during our summer that goes from November to April, otherwise the weather is not so good. You won't feel cold during our winter (average temperature is 20º C), but it rains a lot.
For info on Rio, go to
www.ipanema.com, for info on some paradise beaches in Northeastern Brazil go to:
1) Morro de São Paulo -
http://www.morrodesaopaulo.com.br/main.shtml
2) Porto de Galinhas -
http://www2.uol.com.br/portodegalinhas/index.htm - this is the beach
I've been to. It's really amazing, the best beach on earth.
3) Jericoacoara -
http://www.jericoacoara.com/index.html
4) Pipa -
http://www.pipa.com.br/english/index.html
Any further help, make contact.
conrado.costa@gmail.com