The kite I use most in july in Guincho is my RPM 4.5m (weight 180lb) so packing shouldn't be a problem
The waves, however are hardly ever overhead in the summer.
If the wind is nuking in guincho and it feels like too much to handle, drive south to Costa da Caparica. There are 3 beaches where kiting is allowed (Nova Vaga, Bela Vista and Fonte da Telha/windspirit) and the waves and wind will be mellower than Guincho.
The Azores is really not the best bet in the summer as there are no thermal wind spots. It's much better in the autumn and winter but very difficult to predict as the weather is really unstable. BUT, if you surf, then it's heaven on earth