Thanks everyone for your comments, very much appreciated!
Wow, those waves at Guincho definitely deserve a lot of respect. For Guincho, is there any time in the day when the wind is not as strong e.g. around noon time or closer to sunset?
My favorite kiting playground is the Caribbean / Florida, where I'm used with steady, consistent easterly trade winds, usually in the range of 15-22 knots. Anything close to 30 knots and beyond would be probably out of my comfort zone.
The 7m kite I'm using it mostly in the winter, kiting on snow, ... which btw it's a lot of fun:
So far, it seems that Viana Do Castelo is my best bet, and if the thermals are pushing consistently above 14-15 knots, I should be able to run the 9m.