Alvor is very nice, the lagoon great for flat water - can get crowded sometimes. As this is on the other side of Algarve, save it for some day(s) when travelling there. If you are staying in Faro, check this spot ( http://www.kitebeaches.com/kitebeaches/ ... php?id=712
). You can walk 15/20 minutes to the left edge to run away from crowds.
Not far from Faro, around 30 km towards Spain, you will find Cabanas de Tavira ( http://www.kitebeaches.com/kitebeaches/ ... hp?id=2341
), also a nice spot. Usually you should not need the 7m bow: 9, 11 and 14 cover all your needs for July. Assuming both of you can ride, all sizes are for bow kites and that you ride one size bigger than your girlfriend, she will be using 11 most of the time, sometimes 9 and you will be using 14, sometimes 11. Alvor is stronger, still ok for 9 and 11.