Yep, Ibiraquera and Floripa, August willl be chilly, but you'll have nukin wind and sweet waves.
Just buy a Mormaii wetsuit when you arrive in Floripa, good price, good suits.
Praia Campeche (as does 12 other beaches) has nice waves also, but to be with other kiters, surfers and windsurfers, Ibira is the spot.
I go between the Lagoa in Floripa and Ibiraqera, haven't found a better combo on the planet.
Plus, the after sailing fun is 1st class.
How to get there, a route thru Porto Alegre then switch to GOL will work, flights go thru Sao Paulo also, but POA is a better flight, for me.
I spend the night in POA, then go to Floripa the next day, took the bus last time, not a bad ride, nice bus. Ibiraquera can be found from Floripa by asking any kite shop or any kiter seen in the Lagoa or Praia Mole. The kiters in that area are some of the most fun and friendly you'll encounter, have some fun, I'm heading down for my 179 days this Sept!!