Hello! I found this topic by searching for the concert they are doing here in floripa in a few hours on google... im not a big fan of them but maybe im going with some friends hehe
anyway, i guess i can help you out telling you about some places to go..
about rio, ive been there 2 months ago for 8 days, and actually that was enough to know all the touristic places. sure i could have enjoined much more and seen more stuff, but its possible to know the city in a week.
about florianopolis, well, i live here, and i say its a smaller rio, without a christ hehe
the beaches here are better, and by july there are great waves.
ill write more via email for you, if you wish, just send me a "Hi, it's Paz" to ericoschmitt@yahoo.com.br, or add that same address on MSN messeger (@yahoo.com.br too, not hotmail)
ohh, in rio its hot the whole year, and the water probably also is.. but in florianópolis the water is fucking could the whole year, especially in the winter, when you may surf with penguins around you (yes, ive seen that), so bring a wetsuit, if you dont want to spent around R$500 to buy one here :D